U.S. patent number 8,302,719 [Application Number 12/715,758] was granted by the patent office on 2012-11-06 for vehicle having power stocking mechanism and vehicle system containing the same.
This patent grant is currently assigned to Honda Motor Co., Ltd.. Invention is credited to Satoshi Kanbayashi, Shinichi Kuriyama, Nobuyoshi Muromoto, Dai Nishimura, Kentaro Suzuki, Kazutoshi Takada, Yasuo Watanabe, Muneki Yamada.
United States Patent |
8,302,719 |
Nishimura , et al. |
November 6, 2012 |
Vehicle having power stocking mechanism and vehicle system
containing the same
Abstract
A vehicle including an energy stocking mechanism having an
elastic member connected to the driving wheel of the vehicle so
that power of the driving wheel is stocked as elastic force in the
elastic member and the stocked elastic force is output as power to
the driving wheel, and an output limiter that holds the energy
stocking mechanism when the elastic force is stocked in the elastic
member and releases the holding of the energy stocking mechanism to
output the elastic force when the vehicle starts running. A power
stocking source for stocking elastic force into the energy stocking
mechanism is installed in the vehicle or a station at which the
vehicle stops, and connected to the energy stocking mechanism so
that power from the power stocking source is applied to the energy
stocking mechanism and stocked as the elastic force in the energy
stocking mechanism.
Inventors: |
Nishimura; Dai (Tochigi,
JP), Takada; Kazutoshi (Tochigi, JP),
Kanbayashi; Satoshi (Tochigi, JP), Yamada; Muneki
(Tochigi, JP), Suzuki; Kentaro (Tochigi,
JP), Watanabe; Yasuo (Tochigi, JP),
Kuriyama; Shinichi (Tochigi, JP), Muromoto;
Nobuyoshi (Tochigi, JP) |
Assignee: |
Honda Motor Co., Ltd. (Tokyo,
JP)
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Family
ID: |
42729783 |
Appl.
No.: |
12/715,758 |
Filed: |
March 2, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100230196 A1 |
Sep 16, 2010 |
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Foreign Application Priority Data
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Mar 12, 2009 [JP] |
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2009-058942 |
Mar 12, 2009 [JP] |
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2009-058943 |
Mar 18, 2009 [JP] |
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2009-065810 |
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Current U.S.
Class: |
180/165 |
Current CPC
Class: |
B60L
53/14 (20190201); B60L 8/003 (20130101); B66F
9/22 (20130101); B66F 9/07572 (20130101); Y02T
10/7072 (20130101); Y02T 10/70 (20130101); B60L
2260/28 (20130101); Y02P 90/60 (20151101); Y02T
10/7005 (20130101); Y02T 10/7094 (20130101); Y02T
10/7083 (20130101); B60L 2200/26 (20130101); B60L
2200/44 (20130101); Y02T 90/14 (20130101) |
Current International
Class: |
B60K
6/00 (20071001) |
Field of
Search: |
;180/165 ;701/22,23
;105/35,49 ;104/289 ;74/469,470,473.11 ;446/39-41,44,459,464 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Office Action on the corresponding Chinese patent application
issued May 9, 2012 and English Translation. cited by other.
|
Primary Examiner: Shriver, II; J. Allen
Assistant Examiner: Dolak; James M
Attorney, Agent or Firm: Arent Fox LLP
Claims
What is claimed is:
1. A vehicle running with power from a power source comprising: an
energy stocking mechanism having an elastic member that is
connected to a driving wheel of a vehicle main body, converts power
of the driving wheel to elastic force, stocks the converted elastic
force and outputs the stocked elastic force as power to the driving
wheel; and an output limiter that holds the energy stocking
mechanism while the elastic force is stocked in the elastic member,
and releases the holding of the energy stocking mechanism to output
the elastic force when the vehicle starts running, wherein the
power source is a power stocking source for stocking elastic force
in the energy stocking mechanism, and the energy stocking mechanism
is connectable to the power stocking source so that power from the
power stocking source is applied to the energy stocking mechanism
and stocked as the elastic force in the energy stocking
mechanism.
2. The vehicle according to claim 1, wherein the power stocking
source is installed in the vehicle main body so as to be connected
to the energy stocking mechanism.
3. The vehicle according to claim 1, wherein the output limiter
comprises a gear formed on a shaft connected to the driving wheel,
and a ratchet that has a pawl engaged with the gear to lock the
shaft when the elastic force is stocked in the energy stocking
mechanism and swings the pawl so that the pawl is separated from
the gear when the elastic force is output from the energy stocking
mechanism.
4. The vehicle according to claim 1, wherein the elastic member of
the energy stocking member is formed of a spiral spring that is
wound up around a shaft connected to the driving wheel, and one end
of the spiral spring is connected to an outer periphery of one
shaft end portion of the shaft while the other end of the spiral
spring is connected to a parallel portion that extends in parallel
to the shaft end portion of the shaft and rotates around the shaft
interlockingly with the stocking power source.
5. The vehicle according to claim 1, further comprising a
controller for controlling the output limiter so that the elastic
force stocked in the energy stocking mechanism is allowed to be
output when the vehicle starts running and the rotation of a shaft
is locked when a desired time elapses after the speed of the
vehicle main body reaches a desired speed.
6. The vehicle according to claim 1, further comprising a main
driving wheel for driving the vehicle main body and a running
driving source for driving the main driving wheel, wherein the
power stocked in the elastic member of the energy stocking
mechanism assists driving force of the running driving source.
Description
INCORPORATION BY REFERENCE
The present application claims priority under 35 U.S.C. .sctn.119
to Japanese Patent Application Nos. 2009-058942 and 2009-058943
filed on Mar. 12, 2009 and Japanese Patent Application No.
2009-065810 filed on Mar. 18, 2009. The content of the applications
is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle running with power such
as elastic force stocked in an elastic member, and a vehicle system
containing the vehicle and a station at which the vehicle is
stopped.
2. Description of Related Art
An unmanned automated guided vehicle (AGV: Automated Guided
Vehicle) which runs with power from a battery mounted therein has
been used as a vehicle for conveying a part (work) such as an
engine, a gear box or the like to each working station in a
production field such an automobile factory or the like.
Specifically, in the unmanned automated guide vehicle as described
above, a motor for running is rotationally driven with the power
from the battery to drive driving wheels of the vehicle, whereby
the vehicle runs. With respect to this type of conveying vehicle,
sufficient output power is required to the running motor because it
conveys a heavy object such as an engine part or the like.
Accordingly, there has been concern that the equipment cost and the
power consumption would increase due to increase in size of motors
and thus increase in size of vehicles.
For example, JP-A-2004-331052 discloses a conveying vehicle for
conveying a part (work) such an automatic transmission or the like
which is provided with neither electrically-operated driving system
nor hydraulically operated driving system. In this conveying
vehicle, a rack-and-pinion mechanism is driven due to the empty
weight of a work being conveyed to make forward driving force of
the vehicle, and also the empty weight of the work is stocked in a
coil spring (elastic member) provided to a seat. When the work is
taken out from the seat, the rack-and-pinion is reversely driven by
repulsive force of the coil spring, thereby making backward driving
force of the vehicle.
In this case, the conveying vehicle disclosed in JP-A-2004-331052
can merely reciprocate on a predetermined linear passage, and thus
it is difficult to apply this conveying vehicle to a production
line along which plural kinds of parts are conveyed, assembled with
one another, etc. Furthermore, it is not easy to change the
conveying passage. In addition, the starting operation of the
conveying vehicle is dependent on a work of mounting a work onto
the seat of the vehicle or removing the work from the seat, and
thus the control of the starting operation is cumbersome.
SUMMARY OF THE INVENTION
Therefore, the present invention has been implemented in view of
the foregoing situation, and has an object to provide a vehicle
that can run on a desired moving passage, and easily perform a
starting operation.
Furthermore, the present invention has another object to provide a
vehicle in which power for stocking elastic force in an elastic
member can be reduced to thereby perform energy saving (power
saving).
Still furthermore, the present invention has a further object to
provide a vehicle system that can reduce the weight of a vehicle,
and easily stock elastic force in an elastic member even in a
water-wetted workshop (station).
In order to attain the above objects, according to an aspect of the
present invention, a vehicle running with power from a power source
comprises: an energy stocking mechanism having an elastic member
that is connected to a driving wheel of a vehicle main body,
converts power of the driving wheel to elastic force, stocks the
converted elastic force and outputs the stocked elastic force as
power to the driving wheel; and an output limiter that holds the
energy stocking mechanism while the elastic force is stocked in the
elastic member, and releases the holding of the energy stocking
mechanism to output the elastic force when the vehicle starts
running, wherein the power source is a power stocking source for
stocking elastic force in the energy stocking mechanism, and the
energy stocking mechanism is connectable to the power stocking
source so that power from the power stocking source is applied to
the energy stocking mechanism and stocked as the elastic force in
the energy stocking mechanism.
According to this construction, the energy stocking mechanism is
configured so that the stocking power source is connectable to the
energy stocking mechanism and power is applied from the stocking
power source to the energy stocking mechanism to stock the power as
elastic force in the elastic member of the energy stocking
mechanism. Therefore, by driving the stocking power source, the
elastic force can be stocked in the energy stocking mechanism in
advance, and thus the vehicle can run on a desired moving passage
by using this elastic force. Furthermore, the vehicle is provided
with the output limiter which holds the energy stocking mechanism
under the state that the elastic force is stocked in the elastic
member and also releases the holding concerned to output the
elastic force concerned when the vehicle starts running. Therefore,
the elastic force stocked in the elastic member can be used at a
desired time by a desired amount, and the operation of starting
running can be easily performed.
In the above construction, the power stocking source may be
installed in the vehicle main body so as to be connected to the
energy stocking mechanism. According to this construction, the
connecting operation between the energy stocking mechanism and the
stocking power source is unnecessary, and thus elastic force can be
stocked in the energy stocking mechanism with a simple
construction.
Furthermore, the output limiter may comprise a gear formed on a
shaft connected to the driving wheel, and a ratchet that has a pawl
engaged with the gear to lock the shaft when the elastic force is
stocked in the energy stocking mechanism and swings the pawl so
that the pawl is separated from the gear when the elastic force is
output from the energy stocking mechanism. According to this
construction, the construction of the output limiter can be
simplified. The stock of the elastic force in the energy stocking
mechanism or the output of the elastic force concerned can be
performed by a simple operation of swinging the ratchet.
Still furthermore, the elastic member of the energy stocking member
may be formed of a spiral spring that is wound up around the shaft
connected to the driving wheel, and one end of the spiral spring
may be connected to the outer periphery of one shaft end portion of
the shaft while the other end of the spiral spring is connected to
a parallel portion that extends in parallel to the shaft end
portion of the shaft and rotates around the shaft interlockingly
with the stocking power source. According to this construction, for
example, one element of the shaft and the parallel portion is fixed
so as not to rotate and the other element is rotated by the
stocking power source, whereby elastic force can be stocked in the
spiral spring. Furthermore, the other element of the shaft and the
parallel portion is fixed so as not to rotate and the one element
is rotated by the stocked elastic force, whereby the elastic force
stocked in the spiral spring can be output. In this case, the shaft
and the parallel portion can be rotated in the same direction in
both the stock operation and the output operation. Therefore, the
stock of the elastic force in the energy stocking mechanism or the
output of the elastic force can be smoothly performed.
Still furthermore, the vehicle may further comprise a controller
for controlling the output limiter so that the elastic force
stocked in the energy stocking mechanism is allowed to be output
when the vehicle starts running and the rotation of the shaft is
locked when a desired time containing a zero time elapses after the
speed of the vehicle main body reaches a desired speed containing a
zero speed. According to this construction, for example, the
stocked elastic force can be used only when the vehicle is
accelerated, so that the use efficiency of the elastic force can be
enhanced and also the frequency of the wind-up work based on the
stocking power source can be reduced.
Still furthermore, the vehicle may further comprise a main driving
wheel for driving the vehicle main body and a running driving
source for driving the main driving source, wherein the power
stocked in the elastic member of the energy stocking mechanism
assists driving force of the running driving source. According to
this construction, the power stocked in the elastic force of the
energy stocking mechanism assists the running driving source, and
this assist enables the running driving source to be designed to be
low in power and compact in size, so that weight saving and energy
saving can be performed.
Still furthermore, the vehicle may further comprise a clutch
mechanism for performing a switching operation between output of
power from the elastic member of the energy stocking mechanism to
the driving wheel of the vehicle main body and regeneration of
power from the driving wheel to the elastic member, wherein the
vehicle runs by a prescribed distance, the vehicle starts running
with power stocked in the energy stocking mechanism, and the clutch
mechanism is switched to a regeneration side during running so that
power is generated from the driving wheel to the elastic member
while the vehicle is running. According to this construction, the
clutch mechanism is provided to execute the switching operation
between the output of the power from the elastic member of the
energy stocking mechanism to the driving wheel of the vehicle main
body and the regeneration of power from the driving wheel to the
elastic force. Therefore, by switching the clutch mechanism, the
power of the driving wheel under running can be regenerated
(stocked) as elastic force into the elastic member of the energy
stocking member. Therefore, when the vehicle runs next, the
stocking power source may be driven to supplement the elastic
member of the energy stocking mechanism with extra elastic force to
be added to insufficient elastic force stocked by only the
regeneration. Accordingly, the power for stocking elastic force in
the elastic member can be reduced, and the energy consumption for
driving the stocking power source can be reduced, so that energy
saving can be enhanced.
Still furthermore, the energy stocking mechanism may have a
rotational shaft for winding up the spiral spring as the elastic
member, the rotational shaft may be divided into first and second
rotational shafts, and one end of the spiral spring may be
connected to the outer periphery of a shaft end portion of the
first rotational shaft while the other end of the spiral spring is
integrated with the second rotational shaft and connected to a
parallel portion extending in parallel to the shaft end portion of
the first rotational shaft. According to this construction, for
example, one of the first and second rotational shafts is fixed not
to rotate and the other rotational shaft is rotated by the stocking
power source or the rotational force of the driving wheel, whereby
elastic force can be stocked or regenerated in the spiral spring.
Furthermore, for example, the other rotational shaft of the first
and second rotational shafts is fixed not to rotate and the one
rotational shaft is rotated by the stocked elastic force, whereby
the elastic force stocked in the spiral spring can be output. In
this case, the one rotational shaft rotating in the output
operation is rotated in the same rotational direction as the other
rotational shaft which rotates in the stock or regeneration
operation. Therefore, it is unnecessary to provide a mechanism for
reversing the rotation of the rotational shaft between the stock
(regeneration) operation of the elastic force and the output
operation of the elastic force and connecting the rotational shaft
to the driving wheel, and thus the construction of the energy
stocking mechanism can be simplified.
In this construction, the clutch mechanism may have an output
clutch that is provided to one rotational shaft of the first and
second rotational shafts, connects the driving wheel and the spiral
spring to each other when elastic force stocked in the spiral
spring is output, and separates the driving wheel and the spiral
spring from each other when power is stocked or regenerated into
the spiral spring, and an input clutch that is provided to the
other rotational shaft, separates the driving wheel and the spiral
spring from each other when the stocked elastic force is output,
and connects the driving wheel and the spiral spring to each other
when power is regenerated into the spiral spring. According to this
construction, the rotation or fixing of the first and second
rotational shafts can be simply controlled by the input clutch and
the output clutch. Therefore, the stock of elastic force into the
spiral spring of the energy stocking mechanism and the output of
the elastic force of the spiral spring can be smoothly
controlled.
In this construction, the output limiter may continuously or
stepwise output the stocked elastic force as power in the range
from 0% to 100% to one of the first and second rotational shafts.
According to this construction, the elastic force stocked in the
spiral spring is prevented from being output at a burst, and the
output amount of the elastic force can be controlled. Therefore,
the acceleration and the speed of the vehicle can be properly
controlled. Furthermore, the driving time of the stocking power
source can be reduced by suppressing the output amount of the
elastic force, and thus the energy consumption for driving the
stocking power source can be reduced.
Furthermore, the vehicle may further comprise a main driving wheel
for driving the vehicle main body and a running driving source for
driving the main driving wheel, wherein the power stocked in the
elastic member of the energy stocking mechanism assists driving
force of the running driving source when the vehicle starts
running, and the clutch mechanism is switched to a regeneration
side when the vehicle is located at a position near to an end point
of the predetermined distance so that power from the driving wheel
to the elastic member is regenerated while the vehicle is running.
According to this construction, the power stocked in the elastic
member of the energy stocking mechanism assists the driving force
of the running driving source when the vehicle starts running, and
thus the running driving source can be designed to be low in power
and compact in size, so that weight saving and energy saving can be
performed for the vehicle. Furthermore, when the vehicle is near to
the end point of the predetermined distance, the clutch mechanism
is switched to the regeneration side so that power from the driving
wheel into elastic member can be regenerated while the vehicle is
running. When the vehicle runs next, the stocking power source may
be driven to supplement the energy stocking mechanism with extra
elastic force to be added to insufficient elastic force generated
by only the regeneration. Accordingly, the power for stocking
elastic force in the elastic member can be reduced, and the energy
consumption for driving the stocking power source can be reduced,
so that energy saving can be performed.
Furthermore, the vehicle may run between stations each of which is
provided with the power stocking source, and the energy stocking
mechanism may have a coupling unit that is connectable to the power
stocking source when the vehicle main body stops at each of the
stations.
According to this construction, it is unnecessary to provide the
vehicle with the stocking power source for stocking elastic force
into the elastic member, and thus the vehicle can be designed to be
light in weight and compact in size.
According to another aspect of the present invention, a vehicle
system comprises: a vehicle including a vehicle main body, a
driving wheel and an energy stocking mechanism having an elastic
member that is connected to the driving wheel, converts power of
the driving wheel to elastic force, stocks the converted elastic
force and outputs the stocked elastic force as power to the driving
wheel; and stations at which the vehicle stops, wherein each of the
stations has a stocking power source that is connected to the
energy stocking mechanism of the vehicle to supply power therefrom
into the elastic member of the energy stocking mechanism so that
the supplied power is stocked in the elastic member when the
vehicle stops at the station.
According to this construction, each station is provided with the
stocking power source that is connected to the energy stocking
mechanism of the vehicle to stock power into the elastic member of
the energy stocking mechanism when the vehicle stops at the
station. Therefore, it is unnecessary to provide the vehicle with
the stocking power source, and thus the vehicle can be designed to
be light in weigh and compact in size. Furthermore, only power may
be supplied from the stocking power source of the station to the
energy stocking mechanism of the vehicle main body, and thus
elastic force can be easily stocked into the elastic member even in
a water-wetted field or the like. Furthermore, the stocking power
source is not provided to the vehicle main body, but provided to
the station. Therefore, when the number of stations is smaller than
the number of vehicles, the number of stocking power sources to be
installed is reduced, and thus the system construction can be
implemented in low cost.
In this construction, the vehicle may have a clutch mechanism for
performing a switching operation between output of power from the
elastic member of the energy stocking mechanism to the driving
wheel of the vehicle and regeneration of power from the driving
wheel into the elastic member, and when the vehicle moves between
the stations, the vehicle starts running with power stocked in the
energy stocking mechanism, and the clutch mechanism is switched to
a regeneration side during running so that power is generated from
the driving wheel to the elastic member while the vehicle is
running. According to this construction, the clutch mechanism is
provided to perform the switching operation between the output of
the power from the elastic member of the energy stocking mechanism
to the driving wheel and the regeneration of power from the driving
wheel to the elastic member. Therefore, by switching the clutch
mechanism, the power of the driving wheel during running can be
regenerated (stocked) as elastic force into the elastic member of
the energy stocking mechanism. Therefore, at the station where the
vehicle stops, the stocking power source is driven to supplement
the elastic member of the energy stocking mechanism with elastic
force to be added to insufficient regenerated elastic force.
Accordingly, the power for stocking the elastic force into the
elastic member can be reduced, and the energy consumption for
driving the stocking power source can be reduced, so that energy
saving can be performed.
In this construction, the vehicle may further comprise a main
driving wheel for driving the vehicle main body and a running
driving source for driving the main driving wheel, wherein the
power stocked in the elastic member of the energy stocking
mechanism assists driving force of the running driving source when
the vehicle starts running, and the clutch mechanism is switched to
a regeneration side when the vehicle is located at a position near
to an end point of the distance between the stations so that power
from the driving wheel to the elastic member is regenerated while
the vehicle is running. According to this construction, the power
stocked in the elastic member of the energy stocking mechanism
assists the driving force of the running driving source when the
vehicle starts running, and thus the vehicle can be designed to be
low in power and compact in size, so that weight saving and energy
saving can be performed for the vehicle. Furthermore, the clutch
mechanism is switched to the regeneration side when the vehicle is
near to the end point of the distance between the stations, thereby
enabling regeneration of power from the driving wheel to the
elastic member while the vehicle runs. Therefore, at the station
where the vehicle stops, the stocking power source is driven to
supplement the elastic member of the energy stocking mechanism with
elastic force to be added to insufficient elastic force generated
by only the regeneration. Accordingly, the power for stocking
elastic force into the elastic member can be reduced, and the
energy consumption for driving the stocking power source can be
reduced, so that energy saving can be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially-omitted perspective view showing a conveying
vehicle as an applied example of a vehicle according to a first
embodiment;
FIG. 2 is a partially-omitted side view of the conveying vehicle
shown in FIG. 1;
FIG. 3 is a partially-omitted plan view showing a driving system of
the conveying vehicle shown in FIG. 1;
FIG. 4 is a block diagram showing an electrical system and a
hydraulic system of the conveying vehicle shown in FIG. 1;
FIGS. 5A and 5B are diagrams showing the construction of an
auxiliary driving unit, wherein FIG. 5A is a partially-omitted plan
view of the auxiliary driving unit and FIG. 5B is a
partially-omitted side view of FIG. 5A;
FIG. 6A is a diagram showing an operation when elastic force is
stocked in a spiral spring of an energy stocking mechanism, and
FIG. 6B is a diagram showing an operation when the stocked elastic
force is output to an auxiliary driving wheel;
FIG. 7 is a diagram showing a conveying system to which the
conveying vehicle shown in FIG. 1 is applied;
FIG. 8 is a partially-omitted perspective view showing a conveying
vehicle as an applied example of a vehicle according to a second
embodiment;
FIG. 9 is a partially-omitted side view of the conveying vehicle
shown in FIG. 8;
FIG. 10 is a partially-omitted plan view showing a driving system
of the conveying vehicle shown in FIG. 8;
FIG. 11 is a block diagram showing an electrical system and a
hydraulic system of the conveying vehicle shown in FIG. 8;
FIG. 12A is a diagram showing an operation when elastic force is
stocked in a spiral spring of an energy stock mechanism, FIG. 12B
is a diagram showing an operation when the stocked elastic force is
output to an auxiliary driving wheel, and FIG. 12C is a diagram
showing an operation when the power (driving force) of the
auxiliary driving wheel is regenerated in the spiral spring;
FIG. 13 is a diagram showing a conveying system to which the
conveying vehicle shown in FIG. 8 is applied;
FIG. 14 is a plan view showing a conveying system according to a
third embodiment;
FIG. 15 is a partially-omitted perspective view showing a conveying
vehicle used in the conveying system shown in FIG. 14;
FIG. 16 is a partially-omitted side view of the conveying vehicle
shown in FIG. 15;
FIG. 17 is a partially-omitted plan view showing a driving system
of the conveying vehicle shown in FIG. 15;
FIG. 18 is a block diagram showing an electrical system and a
hydraulic system of the conveying vehicle shown in FIG. 15;
FIG. 19A is a diagram showing an operation when elastic force is
stocked in a spiral spring of an energy stock mechanism, FIG. 19B
is a diagram showing an operation when the stocked elastic force is
output to an auxiliary driving wheel, and FIG. 19C is a diagram
showing an operation when the power (driving force) of the
auxiliary driving wheel is regenerated in the spiral spring;
and
FIG. 20 is a diagram showing the operation of the conveying
system.
PREFERRED EMBODIMENTS ACCORDING TO THE PRESENT INVENTION
Preferred embodiments according to the present invention will be
described with reference to the accompanying drawings. In the
following description, front and rear directions, right and left
directions and up and down directions are defined with respect to a
vehicle. Furthermore, an arrow FR in the figures represents the
forward direction of the vehicle, an arrow R represents the
rightward direction of the vehicle, and the arrow UP represents the
upward direction of the vehicle.
First Embodiment
FIG. 1 is a partially-omitted perspective view of a conveying
vehicle 10 as an applied example of a vehicle according to a first
embodiment, and FIG. 2 is a partially-omitted side view of the
conveying vehicle 10 shown in FIG. 1. FIG. 3 is a partially-omitted
plan view showing the driving system of the conveying vehicle 10
shown in FIG. 2, and FIG. 4 is a block diagram showing an
electrical system and a hydraulic system of the conveying vehicle
10 shown in FIG. 1.
The conveying vehicle 10 is an electrically-operated vehicle which
can run on a desired passage with power from a main power unit 14
using a battery (power supply unit) 12 as a power source, and for
example, it is an unmanned automated guided vehicle (AGV) having a
mount table 16 on which a part (work) such as an engine, a gear box
or the like of a vehicle, and conveys the part to a desired
position in a factory. In the first embodiment, the conveying
vehicle 10 is used as an example of the electrically-operated
vehicle, however, any vehicle such as a passenger car, an
electrically-operate cart, an electric train or the like may be
applied insofar as it can run with electrical power.
The conveying vehicle 10 as described above includes a main driving
unit 14 which is driven under normal running, an auxiliary power
unit 18 which is driven when the vehicle is started from the
stopped state of the conveying vehicle 10 and assists the running
(driving) of the vehicle based on the main power unit 14, a mount
portion 20 including the mount table 16 on which a work W is
mounted, and a controller 22 for comprehensively controlling the
operations of the main power unit 14, the auxiliary power unit 18
and the mount portion 20. The respective parts are mounted on a
vehicle body frame (vehicle main body) 24 covered by a body 23.
The main power unit 14 has a motor for running (a driving source
for running) 28 which is provided substantially at the center
portion of the vehicle body frame 24 in the longitudinal direction
of the vehicle and supported by a support frame 26 bridged in the
vehicle width direction on the vehicle frame 24, a main driving
wheel 30 which is rotatably supported through a shaft by the
support frame 26 and rotationally driven by the driving shaft 28a
of the running motor 28, and a battery 12 for supplying power to
the running motor 28.
For example, the battery 12 is charged by an external power source
31 installed in a predetermined station (described later) when the
conveying vehicle 10 is stopped at the station to be on standby or
perform a work. The conveying vehicle 10 and the external power
source 31 are easily electrically connectable to each other through
a pair of male and female connectors 29 and 33 which can be
detachably fitted to each other by magnetic force, for example (see
FIG. 4).
As shown in FIG. 3, the auxiliary power unit 18 has a unit case 19
provided at the rear portion of the vehicle body frame 24 in the
longitudinal direction of the vehicle, and the unit case 19 is
provided with an energy stocking mechanism 34 having a spiral
spring (elastic member) 32 which can convert power (motive energy)
to elastic force and stock the elastic force and also output the
stocked elastic force as power, an auxiliary (assist) motor (a
driving source for stock) 36 for applying power to the energy
stocking mechanism 34 to make the spiral spring 32 stock the
elastic force, and auxiliary (assist) driving wheels (driving
wheels) 38 which are driven with the power based on the elastic
force stocked in the energy stocking mechanism 34. The unit case 19
is designed in an box-shape which is longer in the longitudinal
direction of the vehicle than in the width direction of the
vehicle, and fixed to the vehicle body frame 24 by plural support
members 21 extending from the side surface portions of the unit
case 19.
As shown in FIGS. 2 and 4, the mount portion 20 has the mount table
16 as a table on which the work W is mounted, and an elevating
device 60 which can move the mount table 16 in the up-and-down
direction and hold the mount table 16 and the work W at a desired
height position.
The elevating device 60 comprises a hydraulic cylinder (elevating
mechanism) 64 for elevating the mount table 16 through a rod 62
fixed to the substantially center lower surface of the mount table
16, and a hydraulic circuit 66 (see FIG. 4) for driving the
hydraulic cylinder 64. The elevating operation of the mount table
16 is executed while the mount table 16 is guided by rails 70
extending in the up-and-down direction of the vehicle in parallel
to the rod 62 at both the sides in the vehicle width direction of a
vertical plate 68 provided at the rear portion of the mount table
16, and guide recess portions 72 which are fixed to the vehicle
body frame 24 side and slidably fitted to the rails 70.
As shown in FIG. 4, the hydraulic circuit 66 is connected through a
control valve mechanism 76 to each of an upper chamber 64a and a
lower chamber 64b of a hydraulic cylinder 64 which are
compartmented by a piston 74 linked to the rod 62. The control
valve mechanism 76 is a valve device for properly switching the
intercommunication state with each of the upper chamber 64a and the
lower chamber 64b of the hydraulic circuit 66 and also properly
switching the flow direction of operating oil, and the operation of
the control valve mechanism 76 is controlled by the controller
22.
A pump 78 for pressurizing and fluidizing the operating oil in the
circuit and a generator (electric generator) 80 which receives the
pressure or flow of the operating oil to generate electric power
are disposed in the hydraulic circuit 66. The power generated by
the generator 80 is charged in an auxiliary battery 82 comprising
an electricity storage element such as a capacitor or the like, a
secondary battery or the like, and then used as driving power for
the pump 78. When the power of the auxiliary battery 82 is
insufficient for the driving power of the pump 78, the battery 12
may be used. Furthermore, it is needless to say that the auxiliary
battery 82 is not provided and the power generated in the generator
80 is charged in the battery 12. In this case, the weight of the
conveying vehicle 10 is reduced by only the weight of the removed
auxiliary battery 82.
The conveying vehicle 10 as described above runs by properly
driving the main driving wheel 30 and the auxiliary driving wheels
38 under the control of the controller 22. However, wheels 84a to
84d which are driven and rotated during the running of the vehicle
based on the main driving wheel 30 and the auxiliary driving wheels
38 are further supported through shafts by the vehicle body frame
24 (see FIG. 3). The wheels 84a and 84b serving as the front wheels
in the forward running direction (the direction of the arrow in
FIG. 1) of the conveying vehicle 10 may be made to function as
steering wheels steered under the control of the controller 22, for
example, or the wheels 84c and 84d serving as the rear wheels may
be made to function as steering wheels.
Furthermore, a sensor 88 (see FIG. 3) for detecting the magnetic
field of a magnetic tape 86 (see FIG. 7) which is attached onto a
passage on which the conveying vehicle 10 runs in a factory and
guides the conveying vehicle 10 is provided at the vehicle bottom
surface side of the conveying vehicle 10. Accordingly, the
conveying vehicle 10 can be magnetically induced. In place of the
above method of guiding the conveying vehicle 10, a method of
laying down a rail on the floor surface and inducing the conveying
vehicle along the rail or other methods may be used.
Next, the auxiliary power unit 18 will be described. FIG. 5 is a
diagram showing the construction of the auxiliary power unit 18,
FIG. 5A is a partially-omitted plan view of the auxiliary power
unit 18, and FIG. 5B is a partially-omitted side view of FIG.
5A.
As described above, the auxiliary power unit 18 has the unit case
19 designed to be long in the longitudinal direction of the
conveying vehicle 10, and the auxiliary motor 36 is disposed in the
unit case 19 as shown in FIG. 5. Furthermore, an intermediate shaft
41, a main shaft 42 and a driving shaft 43 which are disposed
substantially in parallel to the axial line of the auxiliary motor
36 are rotatably supported through shafts by the confronting side
surface portions 19A and 19B of the unit case 19.
The auxiliary motor 36 is fixed to the bottom surface portion 19C
of the unit case 19, and projects to the outside of the unit case
19 through a cutout formed in one side surface portion 19A of the
unit case 19. A first gear 37 is fixed to the motor shaft 36a of
the auxiliary motor 36, and the first gear 37 is engaged with a
second gear 39 fixed to the intermediate shaft 41.
One end of the intermediate shaft 41 is journaled by a bearing
portion 44 secured to one side surface portion 19A of the unit case
19, and the other end of the intermediate shaft 41 is journaled by
a first one-way clutch 45 secured to the other side surface portion
19B of the unit case 19. This first one-way clutch 45 is a
mechanical type clutch, and only when the intermediate shaft 41
rotates in the same direction as the normal rotation direction (the
rotational direction of the intermediate shaft 41 by the driving of
the auxiliary motor 36), the first one-way clutch 45 permits the
rotation of the intermediate shaft 41, whereby the intermediate
shaft 41 is prevented from being rotated in the opposite direction.
Specifically, when the intermediate shaft 41 is about to rotate in
the opposite direction, the first one-way clutch 45 is fitted to
the unit case 19, thereby preventing the rotation of the
intermediate shaft 41 in the opposite direction.
Furthermore, the intermediate shaft 41 is provided with a third
gear d46 disposed between the second gear 39 and the bearing
portion 44, and the third gear 46 has a torque limiter 47 between
the third gear 46 and the intermediate shaft 41. The torque limiter
47 makes the third gear 46 run idle with respect to the
intermediate shaft 41 when external force (torque) of a
predetermined value or more occurs in the third gear 46, and
prevents overload on the auxiliary motor 36.
One end of the main shaft 42 is journaled by a bearing portion 48
secured to one side surface portion 19A of the unit case 19, and
the other end side of the main shaft 42 is journaled by the energy
stocking mechanism 34. Furthermore, in this construction, the
energy stocking mechanism 34 is rotatably supported through a shaft
on the other side surface portion 19B of the unit case 19.
Specifically, the energy stocking mechanism 34 has a main body
portion 49, a fourth gear 50 fixed to the main body portion 49, and
a casing 51 for accommodating the spiral spring 32 as described
above. A through hole 49A through which the main shaft 42
penetrates is formed in the main body portion 49, and the main
shaft 42 is supported in the through hole 49A through a pair of
bearing portions 52.
Furthermore, the fourth gear 50 which is engaged with the third
gear 46 of the intermediate shaft 41 is fitted in the outer
peripheral portion at one end side of the main body portion 49, and
the fourth gear 50 and the main body portion 49C are fixed to each
other through bolts 53. Furthermore, a bearing portion 54 is
provided to the outer peripheral portion 49C at the other end side
of the main body portion 49, and the bearing portion 54 is secured
to the other side surface portion 19B of the unit case 19, whereby
the main body portion 49 is rotatable independently of the main
shaft 42.
The end surface 49D at the other end side of the main body portion
49 projects slightly outwardly as compared with the other side
surface portion 19B of the unit case 19, and the casing 51 is fixed
to the end surface 49D at the other end side by a bolt 55.
Therefore, the casing 51 and the main body portion 49 are rotated
integrally with each other.
The scroll type spiral spring 32 is mounted in the casing 51, and
one end of the spiral spring 32 is fixed to the inner wall surface
51A of the casing 51, and the other end of the spiral spring 32 is
fixed to the outer periphery of the shaft end portion of the main
shaft 42. Accordingly, the spiral spring 32 is wound around the
main shaft 42 on the basis of the rotation of the main shaft 42 or
the casing 51. In the first embodiment, the inner wall surface 51A
of the casing 51 extends in parallel to the shaft end portion 41A
of the main shaft 42, and functions as a parallel portion which
rotates around the main shaft 42 interlockingly with the auxiliary
motor 36.
The main shaft 42 is provided with a stopper mechanism (output
limiter) 40 for stopping the rotation of the main shaft 42 and a
first sprocket 56 between the energy stocking mechanism 34 and the
bearing portion 48. The first sprocket 56 is linked to a second
sprocket 58 of the driving shaft 43 through a chain 57. One side
surface portion 19A of the unit case 19 is provided with a
tensioner 63 for adjusting the tension of the chain 57 suspended
between the first sprocket 56 and the second sprocket 58.
The driving shaft 43 is journaled at both the side surface portions
19A and 19B of the unit case 19 by a pair of bearing portions 59,
and the auxiliary driving wheels 38 are secured to both the shaft
end portions of the driving shaft 43. A second one-way clutch 61 is
provided between the driving shaft 43 and the second sprocket 58.
The second one-way clutch 61 is a mechanical clutch which is
engaged with the driving shaft 43 when the second sprocket 58 is
rotated in the normal rotational direction (the rotational
direction based on the output of the energy stocking mechanism 34)
and releases the engagement thereof and slips when the second
sprocket 58 is rotated in the opposite rotational direction.
The stopper mechanism 40 has a gear body (gear) 65 fixed to the
main shaft 42, and a ratchet portion (ratchet) 67 which is swung so
as to be freely engageable with the gear portion 65A of the gear
body 65. In FIG. 5B, the gear portion 65A is illustrated as being
formed at a part of the outer periphery of the gear body 65 for the
sake of simplicity of drawing, however, the gear portion 65A is
formed over the whole periphery of the gear body 65 in the first
embodiment.
The ratchet portion 67 has a ratchet body 69 which is formed at the
tip portion of the ratchet portion 67 so as to be engaged with the
gear portion 65A, and the ratchet body 69 is freely swingably
supported by a support portion 71 erected from the bottom surface
portion 19C of the unit case 19. Specifically, a pair of
confronting support pieces 71A and 71B are formed at the upper
portion of the support portion 71, and substantially the center
portion 69B of the ratchet body 69 is supported between the support
pieces 71A and 71B through a joint pin 73.
Furthermore, the solenoid actuator 75 is secured at the lower side
of the support portion 71. The solenoid actuator 75 makes the shaft
portion 75A freely movable in the up-and-down direction by
supplying power to a coil (not shown) of the solenoid actuator 75
under the control of the controller 22, and the tip of the shaft
portion 75A is linked to the base end portion 69C of the ratchet
body 69.
Normally (when no power is supplied to the coil), the solenoid
actuator 75 is urged by a coil spring (not shown) or the like so
that the shaft portion 75A is downwardly moved, for example.
Accordingly, the ratchet body 69 is swung around the joint pin 73
so that the pawl 69A is separated from the gear portion 65A as
indicated by a broken line in FIG. 5B, so that the lock of the main
shaft 42 by the ratchet body 69 is released and thus the main shaft
42 is freely rotatable.
On the other hand, by supplying power to the coil of the solenoid
actuator 75, the solenoid actuator 75 generates force for pushing
the shaft portion 75A upwardly, and thus the shaft portion 75A is
upwardly moved against the urging force of the coil spring.
Accordingly, as indicated by a solid line in FIG. 5B, in the
ratchet body 69, the pawl 69A is engaged with the gear portion 65A
of the gear body 65, so that the main shaft 42 is locked and thus
is not rotated.
Next, the running operation of the conveying vehicle 10 according
to the first embodiment will be described.
Under the control of the controller 22, the conveying vehicle 10 is
basically controlled to run (starts running) by using the auxiliary
power unit 18 when it starts running from the stopped state, and
also run by using the main power unit 14 when it normally runs
after the start of running.
For example, when the conveying vehicle 10 is stopped at a standby
station or a working station (described later), the battery 12 of
the conveying vehicle 10 is charged by an external power source 31
provided to the standby station or the working station. Here, when
the conveying vehicle 10 runs (starts running) by using the
auxiliary power unit 18, the controller 22 drives the auxiliary
motor 36 with power form the external power source 31.
At this time, the controller 22 sets the solenoid actuator 75 to an
operating state (ON). That is, by actuating the solenoid actuator
75, the shaft portion 75A is moved upwardly, and the pawl 69A of
the ratchet body 69 is engaged with the gear portion 65A of the
gear body 65. Therefore, the main shaft 42 is locked so that it
does not rotate.
When the auxiliary motor 36 is driven under the state that the main
shaft 42 is locked, the rotation of the normal direction of the
auxiliary motor 36 is transmitted to the first gear 37, the second
gear 39, the intermediate shaft 41, the third gear 46 and the
fourth gear 50 as shown in FIG. 6a. The fourth gear 50 is fixed to
the main body portion 49 of the energy stocking mechanism. 34 and
the casing 51, and thus the casing 51 is rotted integrally with the
fourth gear 50, so that the spiral spring 32 is wound up around the
main shaft 42. Here, when the spiral spring 32 is excessively wound
up, the torque limiter 47 disposed between the third gear 46 and
the intermediate shaft 41 runs idle, and thus the overload on the
auxiliary motor 36 is prevented.
Under this state, elastic force for rotating the casing 51 in the
reverse rotational direction occurs in the spiral spring 32. In the
first embodiment, the intermediate shaft 41 is provided with the
one-way clutch 45 for preventing this reverse rotation of the
intermediate shaft 41, and thus the casing 51 which is gear-linked
to the intermediate shaft 41 is fixed (hold) so as not to rotate in
the reverse rotational direction. As described above, the power
(driving force or rotational torque) of the auxiliary motor 36 is
converted to the elastic force of the spiral spring 32 and stocked
in the energy stocking mechanism 34.
Subsequently, after the charging of the battery 12 by the external
power source 21 and also the stock of the elastic force in the
energy stocking mechanism 34 are completed, the controller 22
starts running (drives forward) on the basis of a running (running
starting) instruction. Specifically, the controller 22 sets the
solenoid actuator 75 to the stopped state (OFF) when receiving the
running start instruction.
When the solenoid actuator 75 is stopped, the pawl 69A of the
ratchet body 69 is separated from the gear portion 65A, and thus
the lock of the main shaft 42 is released. Therefore, as shown in
FIG. 6B, the elastic force of the spiral spring 32 is released, so
that the main shaft 42 is rotated roundly. Here, the rotation of
the casing 51 in the reverse rotational direction is regulated by
the first one-way clutch 45, and thus the main shaft 42 is rotated
normally (in the forward rotational direction) as in the case of
the casing 51 under the stocked state.
According to this construction, the rotational direction of the
casing under the stocking state that the elastic force is being
stocked in the spiral spring 32 can be made identical to the
rotational direction of the main shaft 42 when the elastic force is
being output. Therefore, the stock of elastic force into the energy
stocking mechanism 34 or the output of the elastic force concerned
can be smoothly performed.
The rotational driving force of the main shaft 42 is transmitted to
the driving shaft 43 through the first sprocket 56, the chain 57,
the second sprocket 58 and the second one-way clutch 61, and thus
the driving shaft 43 is rotated, whereby the auxiliary driving
wheels 38 are rotated in such a direction as move the conveying
vehicle 10 forwardly, and thus the conveying vehicle 10 starts
running.
Here, for example, an electromagnetic brake may be adopted as the
stopper mechanism 40 for fixing the rotation of the main shaft 42.
However, the rotational torque transmitted to the main shaft 42
varies in accordance with the characteristic of the spiral spring
32 of the energy stocking mechanism 34 or the residual amount of
the stock, and thus it is required to make a strict selection of
brake to the spiral spring in the construction adopting the
electromagnetic brake, so that the construction of the stopper
mechanism is complicated and the product cost increases.
In the first embodiment, the stopper mechanism 40 comprises the
gear body 65 fixed to the main shaft 42 and the ratchet portion 67
which is swung so as to be freely engageable with the gear portion
65A of the gear body 65. In this construction, the ratchet portion
67 is swung irrespective of the characteristic of the spiral spring
32 so that the ratchet portion 67 is engaged with the gear portion
65A when the rotation of the main shaft 42 is fixed, and the pawl
69A of the ratchet portion 67 is separated from the gear portion
65A when the main shaft 42 is rotated. Therefore, the construction
of the stopper mechanism 40 can be simplified, and the
manufacturing cost can be reduced. In addition, the stock of
elastic force in the energy stocking mechanism 34 or the output of
the elastic force concerned can be performed by a simple operation
of swinging the ratchet portion 67.
In the first embodiment, the controller 22 controls the solenoid
actuator 75 so that the ratchet body 69 is engaged with the gear
portion 65A when a desired time (for example, five seconds) elapses
from the start of running of the conveying vehicle 10. According to
this operation, since the elastic force stocked in the energy
stocking mechanism 34 can be exclusively used for acceleration, the
use efficiency of the elastic force can be enhanced, and the
frequency of the winding frequency of the spiral spring at the
standby station or the working station can be reduced.
Furthermore, the control of the stopper mechanism 40 can be
arbitrarily changed. For example, the ratchet body 60 may be
engaged with the gear portion 65A at the time point when the speed
of the conveying vehicle 10 reaches a desired speed, or a desired
time may be measured from the time point when the speed of the
conveying vehicle 10 reaches the desired speed. In this case, the
speed of the conveying vehicle may be determined by detecting the
rotational number of the driving shaft 43 and calculating the
vehicle speed from the detected rotational number.
At the running start stage based on the auxiliary power unit 18,
the main shaft 42 is rotated to apply rotational torque to the
auxiliary driving wheels 38 at least until the elastic force
stocked in the spiral spring 32 is released. In the first
embodiment, the second one-way clutch 61 is provided between the
driving shaft 43 and the second sprocket 58. Accordingly, even when
the elastic force stocked in the spiral spring 32 is released and
the rotational speed of the main shaft 42 is reduced to be lower
than the rotational speed of the driving shaft 43, the second
one-way clutch 61 slips, so that the rotation of the driving shaft
43 is continued and the conveying vehicle 10 can run at some
distance by the inertial force thereof. Accordingly, the conveying
vehicle 10 can run with only the elastic force stocked in the
spiral spring 32 of the energy stocking mechanism 34 among working
stations in a factory by designing the conveying vehicle 10 in
consideration of the vehicle weight of the conveying vehicle 10
containing a work to be conveyed, the characteristic of the spiral
spring, losses of the respective bearings, etc., for example.
A clutch (not shown) may be disposed between the driving shaft 28a
of the running motor 28 and the main driving wheel 30 so that the
clutch concerned is set to a separation state when the conveying
vehicle 10 starts running by the auxiliary power unit 18. In this
case, the load on the running motor 28 which is not used at the
running start time can be reduced, and also the load from the
running motor 28 can be effectively suppressed from affecting the
running starting operation.
When the running of the conveying vehicle 10 is continued after the
start of running based on the auxiliary power unit 18, the
controller 22 drives the main power unit 14, and drives the running
motor 28 with the power from the battery 12, whereby the conveying
vehicle can continuously run as a normal electrically-operated
vehicle.
As described above, according to the conveying vehicle 10 according
to the first embodiment, the auxiliary driving wheels 38 are driven
by the elastic force stocked in the spiral spring 32 of the energy
stocking mechanism 34, whereby the conveying vehicle 10 can start
running from the stopped state thereof. In this case, the auxiliary
motor 36 which winds up the spiral spring 32 is driven by the
external power source 31 when the conveying vehicle 10 is stopped,
and thus it is unnecessary to consume the battery 12. In addition,
the battery 12 is charged by the external power source 31 at the
same time, so that no time loss occurs. Furthermore after the
conveying vehicle 10 starts running by the auxiliary power unit 18,
the conveying vehicle 10 electrically runs by the main power unit
as in the case of a general electrically-operated vehicle, so that
the conveying vehicle 10 can run on a desired passage by a desired
distance.
Furthermore, in general, the power amount (current amount) of the
motor under low-speed rotation is larger than that under
predetermined high-speed rotation, and also the driving torque
required to start running from a stopped state is very larger than
the driving torque under a stationary running state. In other
words, if the conveying vehicle 10 is made to start running by
using the running motor 28, the running motor 28 must rotate at a
low speed and output a high torque. Therefore, the power
consumption thereof would be extremely larger that the power
consumption of the auxiliary motor 36 for winding the spiral spring
32.
On the other hand, the start of running of the conveying vehicle 10
can be covered by the elastic force of the spiral spring 32, and
thus a low-power and compact motor can be used as the running motor
28. Particularly, with respect to the conveying vehicle 10 which is
also required to convey a work as a heavy load, the load associated
with the start of running is very large, and the effect thereof is
remarkable. Furthermore, in the conveying vehicle 10, it is hardly
required to use the battery 12 at the running start time.
Therefore, the battery 12 can be designed to be small in capacity
and compact in size, and thus weight saving and energy saving for
the conveying vehicle 10 can be performed. In addition, since the
spiral spring is used as the elastic member constituting the energy
stocking mechanism 34, the auxiliary power unit 18 can be
constructed simply and in low cost.
In the conveying vehicle 10 of the first embodiment, the conveying
vehicle 10 according to this invention can be made to run by
selectively driving the main power unit 14 and the auxiliary power
unit 18 as described above, whereby the energy saving can be more
greatly performed as compared with the normal electrically-operated
vehicle. With respect to the elevating device 60 constituting the
mount portion 20 on which a work is mounted, it is provided with
the generator 80, the auxiliary battery 82, etc., whereby energy
saving can be further greatly enhanced.
That is, in the elevating device 60, before the work W is mounted
on the mount table 16, under the control of the controller 22, the
control valve mechanism 76 is first switched and the pump 78 is
driven, and oil pressure is applied in the hydraulic circuit 66 in
a direction of a broken-line arrow P in FIG. 4. Accordingly, the
lower chamber 64b is pressurized, and the mount table 16 is
upwardly moved to a desired height position through the piston
74.
Subsequently, the work W is mounted on the mount table 16. At this
time, by preventing leakage of hydraulic pressure from the lower
chamber 64b through the control valve mechanism 76 and keeping the
pressurized state, the height position of the work W can be kept
easily and with saved power without keeping the driving of the pump
78.
When the work W is mounted on the mount table 16 or the work W held
at the desired height position is downwardly moved, the control
valve mechanism 76 is properly controlled so that the mount table
16 is downwardly moved by the weight of the work W and the mount
table 16 without driving the pump 78. That is, the control valve
mechanism 76 is controlled to be switched so that the operating oil
can flow out from the lower chamber 64b and the flow-out operating
oil flows through the hydraulic circuit 66 in the direction of a
solid-line arrow Q. Accordingly, the operating oil flows out from
the lower chamber 64b which is compressed due to the downward
movement of the piston 74 in connection with the downward movement
of the work W and the mount table 16, so that a vane wheel (not
shown) or the like of the generator 80 is rotated to generate power
and the generated power is stocked in the auxiliary battery 82.
In the elevating device 60, the pump 78 is driven with the stocked
power from the auxiliary battery 82, and the mount table 16 can be
returned to the desired height position. When the power from the
auxiliary battery 82 is insufficient to return the mount table 16
to the desired height position, the battery 12 may be used in
combination.
As described above, in the elevating device 60, power can be
generated in the generator 80 by using the weight of the work W and
the weight of the mount table 16, and utilized as a driving source
of the pump 78 which is used to move the mount table 16 upwardly
again through the auxiliary battery 82. That is, the elevating
device 60 has an energy regenerating mechanism for regenerating the
potential energy of the work W mounted on the mount table 16 at the
desired height position as electrical energy by using the hydraulic
circuit 66 and the generator 80, and charging the auxiliary battery
82. Therefore, basically, the energy required to move the mount
table 16 upwardly and downwardly can be covered by the elevating
device 60 itself.
Accordingly, the conveying vehicle 10 has the elevating device 60
having the energy regenerating mechanism described above, and thus
it is unnecessary to use power of the battery 12 or the like as
elevating energy of the mount table 16. Therefore, the battery 12
can be designed to be smaller in capacity and more compact in size,
and thus the energy saving of the conveying vehicle 10 can be more
greatly enhanced.
As shown in FIG. 4, in the conveying vehicle 10, the electrical
energy which is regenerated by the elevating device 60 and output
from the generator 80 may be used not only to charge the auxiliary
battery 82, but also to derive the auxiliary motor 36 of the
auxiliary power unit 18. Accordingly, even when it is unnecessary
to charge the battery 12 under the stopped state or no external
power source 31 is provided to a station or the like at which the
conveying vehicle is stopped, the auxiliary motor 36 may be driven
with the power from the auxiliary battery 82 without using any
power from the battery 12 to stock elastic force in the energy
stocking mechanism 34.
In addition, the mount table 16 on which the work W is mounted may
be downwardly moved at a desired timing to generate power when the
conveying vehicle 10 is stopped, whereby the power from the
generator 80 is supplied to the auxiliary motor 36 to stock elastic
force in the spiral spring 32 when the conveying vehicle 10 is
stopped. That is, at the stop time of the conveying vehicle 10, the
loading of the work W onto the mount table 16 and the stock of
elastic force into the spiral spring 32 can be simultaneously
performed, and after the work W is loaded, the quick start of
running by the auxiliary power unit 18 can be performed. Therefore,
further energy saving and speed-up of the conveying work can be
performed.
Next, the conveying system 100 to which the conveying vehicle 10
according to the first embodiment is applied will be described.
As shown in FIG. 7, in the conveying system 100, predetermined
works are performed at respective working stations 102a to 102c
while plural conveying vehicles 10 run a passage guided by a
magnetic tape 86 laid down in a factory.
First, a conveying vehicle 10 which is on standby at a standby
station 104 of the conveying system 100 is supplied with power from
the external power source 31 to charge the battery 12 and stock
elastic force in the energy stocking mechanism 34. After the
charging of the battery 12 and the stocking of the elastic force in
the energy stocking mechanism 34 are completed, the conveying
vehicle 10 concerned starts running by using the auxiliary power
unit 18 as a driving source. The conveying vehicle 10 which starts
running is guided by a magnetic tape 86 by detecting magnetic field
through a sensor 88 under the control of the controller 22, and
reaches a first work station 102a. When the distance between the
standby station 104 and the work station 102a is within a
sufficiently reachable distance at which the conveying vehicle
starting from the standby station 104 reaches the work station 102a
by only the power of the auxiliary power unit 18, it is unnecessary
to drive the main power unit 14 after the conveying vehicle 10
starts running, and thus the power can be extremely saved. The same
is applied to the movement between the following respective work
stations.
Subsequently, for example, a work W such as a vehicle engine or the
like is loaded onto the mount table 16 of the conveying vehicle 10
reaching the work station 102a by a working robot 106a provided to
the work station 102a. Furthermore, in the elevating device 60,
energy is regenerated by using the weight of the work W to charge
the auxiliary battery 82 as occasion demands.
When power generation is executed in the elevating device 60
substantially simultaneously with the loading of the work W, the
auxiliary motor 36 may be driven with the generated power, and
elastic force can be stocked in the energy stocking mechanism 34.
In some cases, the external power source 31 may be omitted from the
work station 102a.
The conveying vehicle 10 on which the work W is loaded starts
running by using the auxiliary power unit 18 as the driving source,
and reaches the second work station 102b. At the second work
station 102b, for example, a desired part (not shown) is assembled
with the work W conveyed from the work station 102a by a working
robot 106b.
Subsequently, when the conveying vehicle 10 reaches the third work
station 102c, for example, a working robot 106c conveys the work W
assembled with the desired part from the mount table 16. At the
same time, elastic force is stocked in the energy stocking
mechanism by the external power source 31 again.
Thereafter, the conveying vehicle 10 starting from the work station
102c runs on a passage along which it returns to the standby
station 104 again. At this time, by driving the main power unit 14
after the running start based on the auxiliary power unit 18, the
convey vehicle 10 can easily come back to the standby station 104
even when the distance of the return passage to the standby station
104 is relatively long. The conveying vehicle 10 returning to the
standby station 104 is supplied with power from the external power
source 31 again, and charging of the battery 12 and the stock of
elastic force in the energy stocking mechanism 34 are performed.
Furthermore, by driving the elevating device 60 with the auxiliary
battery 82 charged at the work station 102a, the mount table 16 can
be upwardly moved to a desired height position.
As described above, in the conveying system 100, the conveying
vehicle 10 can move between the respective work stations or the
like with only the power of the auxiliary power unit 18, and thus
the work can be performed with extremely saved power. Of course,
the main power unit 14 can be driven during the movement between
the respective work stations or the like as occasion demands.
In addition, the conveying vehicle 10 can run by using the running
motor 28 as in the case of the normal electrically-operated
vehicle. Therefore, even when the running passage is relatively
long, the conveying vehicle can surely move on the running passage,
and the degree of freedom of the design of the moving passage can
be enhanced. Therefore, as indicated by a broken line of FIG. 7,
the running passage of the conveying vehicle 10 can be easily
changed by re-attaching the magnetic tape 86 and slightly changing
the control program of the controller 22.
As described above, according to the first embodiment, the
auxiliary motor 36 for applying power to the energy stock mechanism
34 to stock elastic force in the spiral spring 32 is provided.
Therefore, by driving the auxiliary motor 36, elastic force can be
stocked in the spiral spring 32 of the energy stocking mechanism 34
in advance at a work station or the like, and the conveying vehicle
10 is enabled to run on a desired moving passage by using the
elastic force concerned. Furthermore, there is provided the stopper
mechanism 40 for holding the energy stocking mechanism 34 under the
state that elastic force is stocked in the spiral spring 32, and
also releasing the holding to output the elastic force when the
conveying vehicle starts running. Therefore, the elastic force
stocked in the spiral spring 32 can be used at any desired time by
a desired amount, and the operation of starting running can be
facilitated.
Furthermore, according to the first embodiment, the stopper
mechanism 40 has the gear body 65 formed in the main shaft 42
linked to the auxiliary driving wheels 38, and the ratchet portion
67 which has the pawl 69A engaged with the gear portion 65A of the
gear body 65 to lock the main shaft 42 when elastic force is
stocked, and is swung so that the pawl 69A is separated form the
gear portion 65A when the elastic force is output. Therefore, the
construction of the stopper mechanism 40 can be simplified. In
addition, the stock of elastic force into the energy stocking
mechanism 34 or the output of the elastic force concerned can be
performed by a simple operation of swinging the ratchet portion
67.
Still furthermore, according to the first embodiment, the energy
stocking mechanism 34 has the spiral spring 32 which is wound up
around the main shaft 42 joined to the auxiliary driving wheels 38,
one end of the spiral spring 32 is joined to the outer periphery of
the shaft end portion of the main shaft 42, and the other end of
the spiral spring 32 extends in parallel to the shaft end portion
of the main shaft 42 and is joined to the inner wall surface 51A of
the casing 51 which rotates around the main shaft 42 interlockingly
with the auxiliary motor 36. Therefore, the rotational direction of
the casing 51 when elastic force is stocked in the spiral spring 32
can be made identical to the rotational direction of the main shaft
42 when the elastic force concerned is output. Therefore, the stock
of elastic force into the energy stocking mechanism 34 or the
output of the elastic force concerned can be smoothly
performed.
According to the first embodiment, the elastic force is output as
power when the conveying vehicle 10 starts running, and also the
controller 22 controls the stopper mechanism 40 so that the
rotation of the main shaft 42 is locked when a desired time
containing zero elapses after the speed of the conveying vehicle 10
reaches a desired speed containing zero. Therefore, the stocked
elastic force can be used for only acceleration of the vehicle.
Therefore, the use efficiency of the elastic force can be enhanced,
and the frequency of the wind-up work at the work station or the
like can be reduced.
Furthermore, according to the first embodiment, the main driving
wheel 30 for driving the vehicle body frame 24 and the running
motor 28 for driving the main driving wheel 30 are provided, and
the power stocked in the spiral spring of the energy stocking
mechanism 34 assists the driving force of the running motor 28 when
the vehicle starts running. Therefore, a low-power and compact
motor can be used as the running motor 28, and the weight saving
and energy saving of the conveying vehicle 10 can be performed.
Second Embodiment
FIG. 8 is a partially-omitted perspective view of a conveying
vehicle 110 as an applied example of a vehicle according to a
second embodiment, and FIG. 9 is a partially-omitted side view of
the conveying vehicle 110 shown in FIG. 8. FIG. 10 is a
partially-omitted plan view showing the driving system of the
conveying vehicle 110 shown in FIG. 9, and FIG. 11 is a block
diagram showing an electrical system and a hydraulic system of the
conveying vehicle 110 shown in FIG. 8.
The conveying vehicle 110 is an electrically-operated vehicle which
can run on a desired passage with power from a main power unit 114
using a battery (power supply unit) 112 as a power source, and for
example, it is an unmanned automated guided vehicle (AGV) having a
mount table 116 on which a part (work) such as an engine, a gear
box or the like of a vehicle, and conveys the part to a desired
position in a factory. In the second embodiment, the conveying
vehicle 110 is used as an example of the electrically-operated
vehicle, however, any vehicle such as a passenger car, an
electrically-operate cart, an electric train or the like may be
applied insofar as it can run with electrical power.
The conveying vehicle 110 as described above includes a main
driving unit 114 which is driven under normal running, an auxiliary
power unit 118 which is driven when the vehicle is started from the
stopped state of the conveying vehicle 110 and assists the running
(driving) of the vehicle based on the main power unit 114, a
loading portion 120 including the mount table 116 on which a work W
is mounted, and a controller 122 for comprehensively controlling
the operations of the main power unit 114, the auxiliary power unit
118 and the loading portion 120. The respective parts are mounted
on a vehicle body frame (vehicle main body) 124 covered by a body
123.
The main power unit 114 has a motor for running (a driving source
for running) 128 which is provided substantially at the center
portion of the vehicle body frame 124 in the longitudinal direction
of the vehicle and supported by a support frame 126 bridged in the
vehicle width direction on the vehicle frame 124, a main driving
wheel 130 which is rotatably supported through a shaft by the
support frame 126 and rotationally driven by the driving shaft 128a
of the running motor 128, and a battery 112 for supplying power to
the running motor 128.
For example, the battery 112 is charged by an external power source
131 installed in a predetermined station (described later) when the
conveying vehicle 110 is stopped at the station to be on standby or
perform a work. The conveying vehicle 110 and the external power
source 131 are easily electrically connectable to each other
through a pair of male and female connectors 129 and 133 which can
be detachably fitted to each other by magnetic force, for example
(see FIG. 11).
As shown in FIGS. 9 and 10, the auxiliary power unit 118 is
provided at the rear portion of the vehicle body frame 124 in the
longitudinal direction of the vehicle, and includes an energy
stocking mechanism 134 having a spiral spring (elastic member) 132
which can convert power (motive energy) to elastic force and stock
the elastic force and also output the stocked elastic force as
power, an auxiliary motor (a driving source for stock) 136 for
applying power to the energy stocking mechanism 134 to make the
spiral spring 132 stock the elastic force, and an auxiliary driving
wheel (driving wheel) 138 which are driven with the power based on
the elastic force stocked in the energy stocking mechanism 134, and
a clutch mechanism 140 for switching output of power from the
spiral spring 132 of the energy stocking mechanism 134 to the
auxiliary driving wheel 138 and the regeneration of power from the
auxiliary driving wheel 138 to the spiral spring 132.
The auxiliary motor 136 is fixed onto a plate bridged in the
vehicle width direction of the vehicle body frame 124, and a main
shaft (rotational shaft) 141 and an intermediate shaft 142 which
are disposed substantially in parallel to the axial line of the
auxiliary motor 136 are rotatably supported through shafts on the
plate 144. A driving shaft 143 (FIG. 9) of the auxiliary driving
wheel 138 is provided at the lower side of the intermediate shaft
142, and the driving shaft 143 is rotatably supported through a
shaft by the vehicle body frame 124.
The main shaft 141 is divided into a first shaft (first rotational
shaft) 141a and a second shaft (second rotational shaft) 141b, and
these first and second shafts 141a and 141b are journaled on the
plate 144 by respective bearing portions 146 and 147. A cylindrical
casing 145 having a bottom is fixed to the axial end portion of the
second shaft 141b, and the shaft end portion of the first shaft 141
extends and the scroll type spiral spring 132 is mounted in the
casing 145. One end of the spiral spring 132 is fixed to the inner
wall surface 145 of the casing 145, and the other end of the spiral
spring 132 is fixed to the outer periphery of the shaft end portion
of the first shaft 141a. Accordingly, the spiral spring 132 is
wound up around the first shaft 141a on the basis of the rotation
of the first shaft 141a and the second shaft 141b. In the second
embodiment, the inner wall surface 145a of the casing 145 functions
as a parallel portion extending in parallel to the shaft end
portion of the first shaft 141a.
The auxiliary motor 136 is a brake-contained motor having a motor
brake 136a. A first sprocket 137 is secured to the motor shaft 136b
of the auxiliary motor 136, and the first sprocket 137 is joined
through a chain 139 to a second sprocket 148 disposed in the second
shaft 141b. A first one-way clutch 149 is provided between the
second sprocket 148 and the second shaft 141b.
The first one-way clutch 149 is designed as a mechanical clutch.
When the second sprocket 148 is rotated in the normal direction
(the direction of the rotation based on the auxiliary motor 136),
the first one-way clutch 149 is engaged with the second shaft 141b.
When the second sprocket 148 is rotated in the reverse rotational
direction, the above engagement is released, and the first one-way
clutch 149 slips.
A third sprocket 150 disposed between the second sprocket 148 and
the casing 145 and an input clutch 151 for performing a switching
operation so that the third sprocket 150 and the second shaft 141b
can be freely brought into contact with or separated from each
other. For example, the input clutch 151 is designed as an
electromagnetic type clutch, and when the input clutch 151 is
engaged under the control of the controller 122, the third sprocket
150 and the second shaft 141b are engaged with each other, and thus
the third sprocket 150 is rotated together with the second shaft
141b. On the other hand, when the engagement of the input clutch
151 is released, the engagement between the third sprocket 150 and
the second shaft 141b is released, and the third sprocket 150 slips
on the second shaft 141b.
Furthermore, a fourth sprocket 152, an output clutch 153 for
performing a switching operation so that the fourth sprocket 152
and the first shaft 141a can be freely brought into contact with or
separated from each other, and a spiral spring brake (output
limiter) 154 for adjusting the rotational amount of the first shaft
141a are disposed between the pair of the bearing portions 146 on
the first shaft 141a. The output clutch 153 is of the same type as
the input clutch 151, and in the second embodiment, the clutch
mechanism 140 is configured to have the input clutch 151 and the
output clutch 153.
The spiral spring brake 154 is an electromagnetic brake, for
example, and it permits or prohibits rotation of the first shaft
141a under the control of the controller 122. Furthermore, the
spiral spring brake 154 can adjust the rotational amount of the
first shaft 141a, and continuously or stepwise outputs elastic
force stocked in the spiral spring 132 of the energy stocking
mechanism 134 as power in the range from 0% to 100%. Accordingly,
the elastic force stocked in the spiral spring 132 is prevented
from being output at a burst and also the output amount thereof can
be controlled, so that the acceleration or speed of the conveying
vehicle 110 can be properly controlled. Furthermore, the driving
time of the auxiliary motor 136 is reduced by suppressing the
output amount, and the power consumption to drive the auxiliary
motor can be reduced, so that energy saving can be implemented.
The intermediate shaft 142 is journaled by a pair of bearing
portions 155 at both the ends thereof on the plate 144, and the
intermediate shaft 142 is provided with a fifth sprocket 157
connected to the third sprocket 150 through a chain 156 and a sixth
sprocket 159 connected to the fourth sprocket 152 through a chain
158, and a second one-way clutch 161 is disposed between the sixth
sprocket 159 and the intermediate shaft 142.
As in the case of the one-way clutch 149, the second one-way clutch
161 is a mechanical type clutch which is engaged with the
intermediate shaft 142 when the sixth sprocket 159 rotates in the
normal rotational direction, and disengages from the intermediate
shaft 142 and slips when the sixth sprocket 159 rotates in the
reverse rotational direction.
A seventh sprocket 163 is provided between the sixth sprocket 159
and the bearing portion 155, and the seventh sprocket 163 is
connected to an eighth sprocket 167 (FIG. 12) provided to the
driving shaft 143 through a chain 165. Accordingly, the rotational
power of the main shaft 141 is transmitted through the intermediate
shaft 142 to the driving shaft 143, and the auxiliary driving wheel
138 is driven.
Furthermore, wheel brakes 169 for regulating the rotation of the
intermediate shaft 142 are disposed between the fifth sprocket 157
and the sixth sprocket 159 on the intermediate shaft 142. These
wheels brakes 169 are electromagnetic brakes, for example, and
under the control of the controller 122, they reduce the rotational
speed of the intermediate shaft 142 or stop the rotation of the
intermediate shaft 142 to thereby control the speed of the
conveying vehicle 110.
As shown in FIGS. 9 and 11, the loading portion 120 has a mount
table 116 as a table on which a work W is mounted, and an elevating
device 160 which can move the mount table 116 in an up-and-down
direction and hold the mount table 116 and the work W at a desired
height position.
The elevating device 160 comprises a hydraulic cylinder (elevating
mechanism) 164 for elevating the mount table 116 through a rod 162
fixed to the substantially center lower surface of the mount table
116, and a hydraulic circuit 166 (see FIG. 11) for driving the
hydraulic cylinder 164. The elevating operation of the mount table
116 is executed while the mount table 116 is guided by rails 170
extending in the up-and-down direction of the vehicle in parallel
to the rod 162 at both the sides in the vehicle width direction of
a vertical plate 168 provided at the rear portion of the mount
table 116, and guide recess portions 172 which are fixed to the
vehicle body frame 124 side and slidably fitted to the rails
170.
As shown in FIG. 11, the hydraulic circuit 166 is connected through
a control valve mechanism 176 to each of an upper chamber 164a and
a lower chamber 164b of a hydraulic cylinder 164 which are
compartmented by a piston 174 linked to the rod 162. The control
valve mechanism 176 is a valve device for properly switching the
intercommunication state with each of the upper chamber 164a and
the lower chamber 164b of the hydraulic circuit 166 and also
properly switching the flow direction of operating oil, and the
operation of the control valve mechanism 176 is controlled by the
controller 122.
A pump 178 for pressurizing and fluidizing the operating oil in the
circuit and a generator (electric generator) 180 which receives the
pressure or flow of the operating oil to generate electric power
are disposed in the hydraulic circuit 166. The power generated by
the generator 180 is charged in an auxiliary battery 182 comprising
an electricity storage element such as a capacitor or the like, a
secondary battery or the like, and then used as driving power for
the pump 178. When the power of the auxiliary battery 182 is
insufficient for the driving power of the pump 178, the battery 112
may be used. Furthermore, it is needless to say that the auxiliary
battery 182 is not provided and the power generated in the
generator 180 is charged in the battery 112. In this case, the
weight of the conveying vehicle 110 is reduced by only the weight
of the removed auxiliary battery 182.
The conveying vehicle 110 as described above runs by properly
driving the main driving wheel 130 and the auxiliary driving wheels
138 under the control of the controller 122. However, wheels 184a
to 184d which are driven and rotated during the running of the
vehicle based on the main driving wheel 130 and the auxiliary
driving wheel 138 are further supported through shafts by the
vehicle body frame 124 (see FIG. 10). The wheels 184a and 184b
serving as the front wheels in the forward running direction (the
direction of the arrow in FIG. 8) of the conveying vehicle 110 may
be made to function as steering wheels steered under the control of
the controller 122, for example, or the wheels 184c and 184d
serving as the rear wheels may be made to function as steering
wheels.
Furthermore, a sensor 188 (see FIG. 10) for detecting the magnetic
field of a magnetic tape 186 (see FIG. 13) which is attached onto a
passage on which the conveying vehicle 110 runs in a factory and
guides the conveying vehicle 110 is provided at the vehicle bottom
surface side of the conveying vehicle 110. Accordingly, the
conveying vehicle 110 can be magnetically induced. In place of the
above method of guiding the conveying vehicle 110, a method of
laying down a rail on the floor surface and inducing the conveying
vehicle along the rail or other methods may be used.
Next, the running operation of the conveying vehicle 110 according
to the second embodiment will be described.
Under the control of the controller 122, the conveying vehicle 110
is basically controlled to run (starts running) by using the
auxiliary power unit 118 when it starts running from the stopped
state, and also run by using the main power unit 114 when it
normally runs after the start of running.
For example, when the conveying vehicle 110 is stopped at a standby
station or a working station (described later), the battery 112 of
the conveying vehicle 110 is charged by an external power source 31
provided to the standby station or the working station. Here, when
the conveying vehicle 110 runs (starts running) by using the
auxiliary power unit 118, the controller 122 drives the auxiliary
motor 136 with power form the external power source 131.
At this time, the controller 122 sets the spiral spring brake 154
to an operating state (ON), and also sets the input clutch 151 and
the output clutch 153 to a separation state (OFF). That is, by
operating the spiral spring brake 154, the first shaft 141a is
fixed so that it does not rotate, and by separating the input
clutch 151, even when the second shaft 141b rotates, this rotation
is prevented from being transmitted to the intermediate shaft
142.
When the auxiliary motor 136 is driven, as shown in FIG. 12A, the
rotation in the normal rotational direction of the auxiliary motor
136 is transmitted to the second shaft 141b through the first
one-way clutch 149, and the second shaft 141b is rotated together
with the casing 145, whereby the spiral spring 132 is wound up
around the first shaft 141a. Under this state, the elastic force
which rotates the second shaft 141b in the reverse rotational
direction occurs in the spiral spring 132. Therefore, the
controller 122 operates (turns on) the motor brake 136a of the
auxiliary motor 136, whereby the motor shaft 136b and the second
shaft 141b are fixed so that they do not rotate in the reverse
rotational direction. As described above, in the energy stocking
mechanism 134, the power (rotational torque) of the auxiliary motor
136 is converted to elastic force of the spiral spring 132 and
stocked.
Next, after the charging of the battery 112 by the external power
source 131 and the stock of the elastic force in the energy
stocking mechanism 134 are completed, a preparation for start of
running (start moving) is made. That is, the controller 122 sets
the output clutch 153 to a connection state (ON). Accordingly, the
fourth sprocket 152 and the first shaft 141a are engaged with each
other, and the fourth sprocket 152 can be rotated together with the
rotation of the first shaft 141a, so that the power (rotational
force) of the first shaft 141a is allowed to be transmitted to the
auxiliary driving wheel 138 through the intermediate shaft 142 and
the driving shaft 143. In this case, the holding based on the
spiral spring brake 154 which sets the first shaft 141a to the
rotation-stopped state, and the holding based on the motor brake
136a which sets the second shaft 141b to the rotation-stopped state
are continued.
When the spiral spring brake 154 is released, as shown in FIG. 12B,
the elastic force of the spiral spring 132 is released, so that the
first shaft 141a is roundly rotated. Accordingly, the rotational
driving force of the first shaft 141a is transmitted to the driving
shaft 143 through the fourth sprocket 152, the chain 158, the sixth
sprocket 159, the second one-way clutch 161, the intermediate shaft
142, the seventh sprocket 163, the chain 165 and the eighth
sprocket 167, whereby the driving shaft 143 is rotated.
Accordingly, the auxiliary driving wheel 138 is rotated so that the
conveying vehicle 110 moves forwardly, and thus the conveying
vehicle 110 can start running (moving).
With respect to the start of running based on the auxiliary power
unit 118 as described above, the first shaft 141a is rotated to
apply a rotational torque to the auxiliary driving wheel 138 at
least until the elastic force stocked in the spiral spring 132 is
released. Furthermore, the second one-way clutch 161 is provided
between the intermediate shaft 142 and the sixth sprocket 159.
Therefore, even when the elastic force stocked in the spiral spring
132 is released and the rotational speed of the first shaft 141a is
lower than the rotational speed of the intermediate shaft 142, the
second one-way clutch 161 slips and thus the rotation of the
intermediate shaft 142 and the driving shaft 143 is continued, so
that the conveying vehicle 110 can run by some degree of distance
with the inertial force thereof. Accordingly, the conveying vehicle
110 can run with only the elastic force stocked in the spiral
spring 132 of the energy stocking mechanism 134 among working
stations in a factory by designing the conveying vehicle 110 in
consideration of the vehicle weight of the conveying vehicle 110
containing a work to be conveyed, the characteristic of the spiral
spring 132, losses of the respective bearings, etc., for
example.
A clutch (not shown) may be disposed between the driving shaft 128a
of the running motor 128 and the main driving wheel 130 so that the
clutch concerned is set to a separation state when the conveying
vehicle 110 starts running by the auxiliary power unit 118. In this
case, the load on the running motor 28 which is not used at the
running start time can be reduced, and also the load from the
running motor 128 can be effectively suppressed from affecting the
running starting operation.
When the running of the conveying vehicle 110 is continued after
the start of running based on the auxiliary power unit 118, the
controller 122 drives the main power unit 114, and drives the
running motor 128 with the power from the battery 112, whereby the
conveying vehicle can continuously run as a normal
electrically-operated vehicle.
Subsequently, when the conveying vehicle 110 runs, the controller
122 executes an operation of regenerating the rotational power of
the auxiliary driving wheel 138 to the spiral spring 132 of the
energy stocking mechanism 134. In this case, from the viewpoint of
energy, it is more desired to execute the regenerating operation
during deceleration of the conveying vehicle 110 than during
running of the conveying vehicle 110 based on the running motor
128.
When the conveying vehicle 110 shifts to a decelerating operation,
the controller 122 sets the spiral spring brake 154 to the
operating state (ON), and also sets the input clutch 151 to the
connection state (ON), whereby the third sprocket 150 and the
second shaft 141b are engaged with each other. Accordingly, the
rotational driving force of the auxiliary wheel 138 is transmitted
to the second shaft 141b through the driving shaft 143, the eighth
sprocket 167, the chain, the seventh sprocket 163, the intermediate
shaft 142, the fifth sprocket 157, the chain 156 and the third
sprocket 150, and the casing 145 is rotated together with the
second shaft 141b, whereby the spiral spring 132 is wound up around
the first shaft 141a.
As described above, in this construction, the input clutch 151 is
set to the connection state (ON) during the running of the
conveying vehicle 110, whereby the rotational driving force of the
auxiliary driving wheel 138 can be regenerated (stocked) as the
elastic force of the spiral spring 132. Therefore, in the next
running operation, the auxiliary motor 136 may be driven at a
station to supplement the spiral spring 132 of the energy stocking
mechanism 134 with elastic force which is not enough even by the
regeneration. Accordingly, the power for stocking the elastic force
into the spiral spring 132 can be reduced, and the power
consumption for driving the auxiliary motor 136 can be reduced, so
that energy saving can be implemented.
In a general vehicle in which elastic force is stocked by winding
up a spiral spring around a rotational shaft, the rotational
direction of the rotational shaft when elastic force is stocked is
opposite to the rotational direction of the rotational shaft when
the stocked elastic force is output (released). Therefore, when
elastic force is output to a shaft rotating in a fixed direction
under normal running (for example, forward running) and elastic
force is generated by using the rotational driving force of this
shaft as in the case of the driving shaft of the conveying vehicle,
it is necessary to provide a mechanism for reversing the rotational
shaft of the spiral spring between the output operation and the
regenerating operation. Therefore, the construction of the vehicle
is complicated.
On the other hand, according to the construction of this
embodiment, the energy stocking mechanism 134 has the divided first
and second shafts 141a and 141b and the spiral spring 132 disposed
between these shafts, and thus the first shaft 141a and the second
shaft 141b can be rotated in the same rotational direction in the
output operation of outputting the elastic force stocked in the
spiral spring 132 to the auxiliary driving wheel 138 and in the
regenerating operation of regenerating (stocking) the rotational
driving force of the auxiliary driving wheel 138 as the elastic
force into the spiral spring 132. Therefore, it is unnecessary to
provide a mechanism for reversing the rotation of the rotational
shaft between the elastic force stocking (regenerating) operation
and the elastic force outputting operation, and thus the
construction of the energy stocking mechanism can be
simplified.
As described above, according to the conveying vehicle 110 of the
second embodiment, the auxiliary driving wheel 138 is driven by the
elastic force stocked in the spiral spring 132 of the energy
stocking mechanism 134, whereby the conveying vehicle can start
running from the stopped state. In this case, the auxiliary motor
136 for winding up the spiral spring 132 is driven by the external
power source 131 when the conveying vehicle 110 is stopped.
Therefore, it is unnecessary to consume the battery 112, and also
the auxiliary motor 136 can be driven simultaneously with charging
of the battery 112, so that no time loss occurs. Furthermore, after
the conveying vehicle 110 starts running by using the auxiliary
power unit 118, the conveying vehicle can electrically run by using
the main power unit 114 as in the case of a general
electrically-operated vehicle. Therefore, the conveying vehicle can
run on a desired passage by a desired distance.
Furthermore, in general, the power amount (current amount) of the
motor under low-speed rotation is larger than that under
predetermined high-speed rotation, and also the driving torque
required to start running from a stopped state is very larger than
the driving torque under a stationary running state. In other
words, if the conveying vehicle 110 is made to start running by
using the running motor 28, the running motor 128 must rotate at a
low speed and output a high torque. Therefore, the power
consumption thereof would be extremely larger that the power
consumption of the auxiliary motor 136 for winding the spiral
spring 132.
On the other hand, the start of running of the conveying vehicle
110 can be covered by the elastic force of the spiral spring 132,
and thus a low-power and compact motor can be used as the running
motor 128. Particularly, with respect to the conveying vehicle 110
which is also required to convey a work as a heavy load, the load
associated with the start of running is very large, and the effect
thereof is remarkable. Furthermore, in the conveying vehicle 110,
it is hardly required to use the battery 112 at the running start
time. Therefore, the battery 112 can be designed to be small in
capacity and compact in size, and thus weight saving and energy
saving for the conveying vehicle 110 can be performed. In addition,
since the spiral spring is used as the elastic member constituting
the energy stocking mechanism 134, the auxiliary power unit 118 can
be constructed simply and in low cost.
In the conveying vehicle 110 of the first embodiment, the conveying
vehicle 110 according to this invention can be made to run by
selectively driving the main power unit 114 and the auxiliary power
unit 118 as described above, whereby the energy saving can be more
greatly performed as compared with the normal electrically-operated
vehicle. With respect to the elevating device 160 constituting the
mount portion 120 on which a work is mounted, it is provided with
the generator 180, the auxiliary battery 182, etc., whereby energy
saving can be further greatly enhanced.
That is, in the elevating device 160, before the work W is mounted
on the mount table 116, under the control of the controller 122,
the control valve mechanism 176 is first switched and the pump 178
is driven, and oil pressure is applied in the hydraulic circuit 166
in a direction of a broken-line arrow P in FIG. 11. Accordingly,
the lower chamber 164b is pressurized, and the mount table 116 is
upwardly moved to a desired height position through the piston
174.
Subsequently, the work W is mounted on the mount table 116. At this
time, by preventing leakage of hydraulic pressure from the lower
chamber 164b through the control valve mechanism 176 and keeping
the pressurized state, the height position of the work W can be
kept easily and with saved power without keeping the driving of the
pump 178.
When the work W is mounted on the mount table 116 or the work W
held at the desired height position is downwardly moved, the
control valve mechanism 176 is properly controlled so that the
mount table 116 is downwardly moved by the weight of the work W and
the mount table 116 without driving the pump 178. That is, the
control valve mechanism 176 is controlled to be switched so that
the operating oil can flow out from the lower chamber 164b and the
flow-out operating oil flows through the hydraulic circuit 166 in
the direction of a solid-line arrow Q. Accordingly, the operating
oil flows out from the lower chamber 164b which is compressed due
to the downward movement of the piston 174 in connection with the
downward movement of the work W and the mount table 116, so that a
vane wheel (not shown) or the like of the generator 180 is rotated
to generate power and the generated power is stocked in the
auxiliary battery 182.
In the elevating device 160, the pump 178 is driven with the
stocked power from the auxiliary battery 182, and the mount table
116 can be returned to the desired height position. When the power
from the auxiliary battery 182 is insufficient to return the mount
table 116 to the desired height position, the battery 112 may be
used in combination.
As described above, in the elevating device 160, power can be
generated in the generator 180 by using the weight of the work W
and the weight of the mount table 116, and utilized as a driving
source of the pump 178 which is used to move the mount table 116
upwardly again through the auxiliary battery 182. That is, the
elevating device 160 has an energy regenerating mechanism for
regenerating the potential energy of the work W mounted on the
mount table 116 at the desired height position as electrical energy
by using the hydraulic circuit 166 and the generator 180, and
charging the auxiliary battery 182. Therefore, basically, the
energy required to move the mount table 116 upwardly and downwardly
can be covered by the elevating device 160 itself.
Accordingly, the conveying vehicle 110 has the elevating device 160
having the energy regenerating mechanism described above, and thus
it is unnecessary to use power of the battery 112 or the like as
elevating energy of the mount table 116. Therefore, the battery 112
can be designed to be smaller in capacity and more compact in size,
and thus the energy saving of the conveying vehicle 110 can be more
greatly enhanced.
As shown in FIG. 11, in the conveying vehicle 110, the electrical
energy which is regenerated by the elevating device 160 and output
from the generator 180 may be used not only to charge the auxiliary
battery 182, but also to derive the auxiliary motor 136 of the
auxiliary power unit 118. Accordingly, even when it is unnecessary
to charge the battery 112 under the stopped state or no external
power source 131 is provided to a station or the like at which the
conveying vehicle is stopped, the auxiliary motor 136 may be driven
with the power from the auxiliary battery 182 without using any
power from the battery 112 to stock elastic force in the energy
stocking mechanism 134.
In addition, the mount table 116 on which the work W is mounted may
be downwardly moved at a desired timing to generate power when the
conveying vehicle 110 is stopped, whereby the power from the
generator 180 is supplied to the auxiliary motor 136 to stock
elastic force in the spiral spring 132 when the conveying vehicle
110 is stopped. That is, at the stop time of the conveying vehicle
110, the loading of the work W onto the mount table 116 and the
stock of elastic force into the spiral spring 132 can be
simultaneously performed, and after the work W is loaded, the quick
start of running by the auxiliary power unit 118 can be performed.
Therefore, further energy saving and speed-up of the conveying work
can be performed.
Next, the conveying system 200 to which the conveying vehicle 110
according to the second embodiment is applied will be
described.
As shown in FIG. 13, in the conveying system 200, predetermined
works are performed at respective working stations 202a to 202c
while plural conveying vehicles 110 run a passage guided by a
magnetic tape 186 laid down in a factory.
First, a conveying vehicle 110 which is on standby at a standby
station 204 of the conveying system 200 is supplied with power from
the external power source 131 to charge the battery 112 and stock
elastic force in the energy stocking mechanism 134. After the
charging of the battery 112 and the stocking of the elastic force
in the energy stocking mechanism 134 are completed, the conveying
vehicle 110 concerned starts running by using the auxiliary power
unit 118 as a driving source. The conveying vehicle 110 which
starts running is guided by a magnetic tape 186 by detecting
magnetic field through a sensor 188 under the control of the
controller 122, and reaches a first work station 202a.
In this case, in the energy stocking mechanism 134, the rotational
driving force of the auxiliary driving wheels 38 are regenerated as
elastic force in the spiral spring 132 under the deceleration of
the conveying vehicle 110. Therefore, at the work station 202a, the
auxiliary motor 136 may be driven to supplement the spiral spring
132 of the energy stocking mechanism with elastic force which is
not enough even by the regeneration. Accordingly, the power for
stocking the elastic force in the spiral spring 132 can be reduced,
and the power consumption for driving the auxiliary motor 136 can
be reduced, so that energy saving can be performed.
When the distance between the standby station 204 and the work
station 202a is within a sufficiently reachable distance at which
the conveying vehicle starting from the standby station 104 reaches
the work station 102a by only the power of the auxiliary power unit
118, it is unnecessary to drive the main power unit 114 after the
conveying vehicle 110 starts running, and thus the power can be
extremely saved. The same is applied to the movement between the
following respective work stations.
Subsequently, for example, a work W such as a vehicle engine or the
like is loaded onto the mount table 116 of the conveying vehicle
110 reaching the work station 202a by a working robot 106a provided
to the work station 202a. Furthermore, in the elevating device 160,
energy is regenerated by using the weight of the work W to charge
the auxiliary battery 182 as occasion demands.
When power generation is executed in the elevating device 160
substantially simultaneously with the loading of the work W, the
auxiliary motor 36 may be driven with the generated power, and
elastic force can be stocked in the energy stocking mechanism 134.
In some cases, the external power source 131 may be omitted from
the work station 202a.
The conveying vehicle 110 on which the work W is loaded starts
running by using the auxiliary power unit 118 as the driving
source, and reaches the second work station 202b. At the second
work station 202b, for example, a desired part (not shown) is
assembled with the work W conveyed from the work station 202a by a
working robot 206b.
Subsequently, when the conveying vehicle 110 reaches the third work
station 202c, for example, a working robot 206c conveys the work W
assembled with the desired part from the mount table 116. At the
same time, elastic force is stocked in the energy stocking
mechanism by the external power source 131 again.
Thereafter, the conveying vehicle 110 starting from the work
station 202c runs on a passage along which it returns to the
standby station 204 again. At this time, by driving the main power
unit 114 after the running start based on the auxiliary power unit
118, the convey vehicle 110 can easily come back to the standby
station 204 even when the distance of the return passage to the
standby station 204 is relatively long. The conveying vehicle 110
returning to the standby station 204 is supplied with power from
the external power source 131 again, and charging of the battery
112 and the stock of elastic force in the energy stocking mechanism
134 are performed. Furthermore, by driving the elevating device 160
with the auxiliary battery 82 charged at the work station 202a, the
mount table 116 can be upwardly moved to a desired height
position.
As described above, in the conveying system 200, the conveying
vehicle 110 can move between the respective work stations or the
like with only the power of the auxiliary power unit 118, and thus
the work can be performed with extremely saved power. Of course,
the main power unit 114 can be driven during the movement between
the respective work stations or the like as occasion demands.
In addition, the conveying vehicle 110 can run by using the running
motor 128 as in the case of the normal electrically-operated
vehicle. Therefore, even when the running passage is relatively
long, the conveying vehicle can surely move on the running passage,
and the degree of freedom of the design of the moving passage can
be enhanced. Therefore, as indicated by a broken line of FIG. 13,
the running passage of the conveying vehicle 110 can be easily
changed by re-attaching the magnetic tape 86 and slightly changing
the control program of the controller 122.
As described above, according to the second embodiment, the
conveying vehicle is provided with the energy stocking mechanism
134 having the spiral spring 132 which is connected to the
auxiliary driving wheel 138 of the vehicle body frame 124 so that
the power (driving force) of the auxiliary driving wheel 138 is
converted to elastic force and the thus-converted elastic force is
stocked, and also can output the stocked elastic force to the
auxiliary driving wheels as power (driving force), the auxiliary
motor 136 for stocking power into the spiral spring 132 of the
energy stocking mechanism 134, and the clutch mechanism 140 for
performing the switching operation between the output of the power
from the spiral spring 132 of the energy stocking mechanism 134 to
the auxiliary driving wheel 138 of the vehicle body frame 124 and
the regeneration of power from the auxiliary driving wheel 138 to
the spiral spring. Furthermore, when the conveying vehicle moves by
a prescribed distance, the vehicle conveying runs with the power
stocked in the energy stocking mechanism 134, and the clutch
mechanism 140 is switched to the regeneration side during running,
whereby it is possible to generate the power from the auxiliary
driving wheel 138 to the spiral spring while the conveying vehicle
runs. Therefore, by switching the clutch mechanism 140, the power
of the auxiliary driving wheel 138 under running can be regenerated
(stocked) as elastic force into the spiral spring 132 of the energy
stocking mechanism 134. Accordingly, when the conveying vehicle
runs next, the auxiliary motor 136 may be driven to supplement the
spiral spring 132 of the energy stocking mechanism 134 with elastic
force to be added to insufficient elastic force stocked by only the
regeneration. Accordingly, the power for stocking the elastic force
in the spiral spring 132 can be reduced, and the power consumption
for driving the auxiliary motor 136 can be reduced, whereby energy
saving can be performed.
Furthermore, according to the second embodiment, the energy
stocking mechanism 134 has the main shaft 141 for winding up the
spiral spring 132, the main shaft 141 is divided into the first
shaft 141a and the second shaft 141b, one end of the spiral spring
132 is connected to the outer periphery of the shaft end portion of
the first shaft 141a, and the other end of the spiral spring 132 is
connected to the inner wall surface 145a of the cylindrical casing
145 fixed to the shaft end of the second shaft 141b. Therefore, the
first shaft 141a and the second shaft 141b can be rotated in the
same rotational direction between the output operation in which the
second shaft 141b is fixed and the first shaft 141a is rotated to
output the elastic force stocked in the spiral spring 132 to the
auxiliary driving wheel 138 and the stocking operation in which the
first shaft 141a is fixed and the second shaft 141b is rotated to
regenerate (stock) the rotational driving force of the auxiliary
motor 136 and the auxiliary driving wheel 138 as elastic force into
the spiral spring 132. Therefore, it is unnecessary to provide a
mechanism of reversing the rotation of the rotational shaft and
connecting the rotational shaft to the driving wheels in the
stocking (regenerating) operation of elastic force and the output
operating of the stocked elastic force, and thus the construction
of the energy stocking mechanism can be simplified.
Furthermore, according to the second embodiment, the clutch
mechanism 140 has the output clutch 153 disposed on the first shaft
141a to connect the auxiliary driving wheel 138 to the spiral
spring 132 in the output operation of outputting the stocked
elastic force and also separate the auxiliary driving wheel 138
from the spiral spring 132 in the stocking operation of power into
the spiral spring 132 and in the regenerating operation, and the
input clutch 151 disposed on the second shaft 141b to separate the
auxiliary driving wheel 138 from the spiral spring 132 in the
output operation of the stocked elastic force and connect the
auxiliary driving wheel 138 to the spiral spring 132 in the
regenerating operation of power into the spiral spring 132.
Therefore, on the basis of the connection/separation of the input
clutch 151 and the output clutch 153, the rotation/fixing of the
first shaft 141a and the second shaft 141b can be simply
controlled. Therefore, the stock of elastic force into the spiral
spring 132 of the energy stocking mechanism 134 and the output of
elastic force in the spiral spring 132 can be smoothly
controlled.
Furthermore, according to the second embodiment, the first shaft
141a is provided with the spiral brake 154 which continuously or
stepwise outputs the stocked elastic force as power in the range
from 0% to 100%. Therefore, the elastic force stocked in the spiral
spring 132 can be prevented from being output at a burst and the
output amount can be controlled, so that the acceleration and the
speed of the conveying vehicle 110 can be properly controlled.
Furthermore, the driving time of the auxiliary motor 136 is reduced
by suppressing the output amount, and thus the power consumption
for driving the auxiliary motor 136 can be reduced.
According to the second embodiment, the main driving wheel 130 for
driving the vehicle body frame 124 and the running motor 128 for
driving the main driving wheel 130 are provided, and the power
stocked in the spiral spring of the energy stocking mechanism 134
assists the driving force of the running motor 128 when the vehicle
starts running. Therefore, a low-power and compact motor may be
used as the running motor 128, and weight saving and energy saving
of the conveying vehicle 110 can be performed.
Furthermore, by switching the clutch mechanism 140 to the
regeneration side when the vehicle is located at a position near to
the end point of the distance between the respective work stations,
the regeneration of power from the auxiliary driving wheel 138 to
the spiral spring 132 is enabled while the conveying vehicle runs.
Therefore, at a work station at which the conveying vehicle is
stopped, the auxiliary motor 136 may be driven to supplement the
spiral spring 132 of the energy stocking mechanism 134 with elastic
force to be added to insufficient elastic force stocked by only the
regeneration. Accordingly, the power for stocking the elastic force
in the spiral spring 132 can be reduced, and the power consumption
for driving the auxiliary motor 136 can be reduced, whereby energy
saving can be performed.
Third Embodiment
FIG. 14 is a partially-omitted plan view showing a conveying system
(vehicle system) 300 according to a third embodiment. The conveying
system 300 is introduced to a production field of a vehicle factory
or the like, for example, and it is configured to contain work
stations 302a to 302c provided in a factory, and plural conveying
vehicles 310 that load works W such as an engine, a gear box, etc.
of a vehicle onto a mount table 316 and convey the works W to the
respective work stations 302a to 302c.
The respective work stations 302a to 302c are connected to one
another through a magnetic tap 386 laid down in the factory, and
the conveying vehicles 310 run on a passage guided by the magnetic
tape 386. Working robots 306a and 306b and a worker 307 are
disposed, and execute a work of assembling desired parts (not
shown) of the works W conveyed by the conveying vehicles 310.
Furthermore, each of the work stations 302a to 302c is provided
with an external power source 331 for charging a battery (described
later) of each conveying vehicle 310 when the conveying vehicle 310
is stopped at each of the work stations 302a to 302c, and a wind-up
motor (stocking power source) 336 for winding up the spiral spring
(described later) of the energy stocking mechanism of the conveying
vehicle 310 and stocking power.
Next, the conveying vehicle 310 will be described. FIG. 15 is a
partially-omitted perspective view of a conveying vehicle 310 as an
applied example of a vehicle according to a third embodiment, and
FIG. 16 is a partially-omitted side view of the conveying vehicle
310 shown in FIG. 15. FIG. 17 is a partially-omitted plan view
showing the driving system of the conveying vehicle 310 shown in
FIG. 15, and FIG. 18 is a block diagram showing an electrical
system and a hydraulic system of the conveying vehicle 10 shown in
FIG. 15.
The conveying vehicle 310 is an electrically-operated vehicle which
can run on a desired passage with power from a main power unit 314
using a battery (power supply unit) 312 as a power source, and for
example, it is an unmanned automated guided vehicle (AGV) having a
mount table 316 on which a work W such as an engine, a gear box or
the like of a vehicle, and conveys the part to a desired position
in a factory. In the third embodiment, the conveying vehicle 310 is
used as an example of the electrically-operated vehicle, however,
any vehicle such as a passenger car, an electrically-operate cart,
an electric train or the like may be applied insofar as it can run
with electrical power.
The conveying vehicle 310 as described above includes a main
driving unit 314 which is driven under normal running, an auxiliary
power unit 318 which is driven when the vehicle is started from the
stopped state of the conveying vehicle 310 and assists the running
(driving) of the vehicle based on the main power unit 314, a
loading portion 320 including the mount table 316 on which a work W
is mounted, and a controller 322 for comprehensively controlling
the operations of the main power unit 314, the auxiliary power unit
318 and the loading portion 320. The respective parts are mounted
on a vehicle body frame (vehicle main body) 324 covered by a body
323.
The main power unit 314 has a motor for running (a driving source
for running) 328 which is provided substantially at the center
portion of the vehicle body frame 324 in the longitudinal direction
of the vehicle and supported by a support frame 326 bridged in the
vehicle width direction on the vehicle frame 324, a main driving
wheel 330 which is rotatably supported through a shaft by the
support frame 326 and rotationally driven by the driving shaft 328a
of the running motor 328, and a battery 312 for supplying power to
the running motor 328.
For example, the battery 312 is charged by an external power source
131 installed in a predetermined station when the conveying vehicle
310 is stopped at the station to be on standby or perform a work.
The conveying vehicle 310 and the external power source 331 are
easily electrically connectable to each other through a pair of
male and female connectors 329 and 333 which can be detachably
fitted to each other by magnetic force, for example (see FIG.
18).
As shown in FIGS. 16 and 17, the auxiliary power unit 318 is
provided at the rear portion of the vehicle body frame 324 in the
longitudinal direction of the vehicle, and includes an energy
stocking mechanism 334 having a spiral spring (elastic member) 332
which can convert power (motive energy) to elastic force and stock
the elastic force and also output the stocked elastic force as
power, an auxiliary driving wheel (driving wheel) 338 which is
driven with the power based on the elastic force stocked in the
energy stocking mechanism 334, and a clutch mechanism 340 for
switching output of power from the spiral spring 332 of the energy
stocking mechanism 334 to the auxiliary driving wheel 338 and the
regeneration of power from the auxiliary driving wheels 338 to the
spiral spring 332.
A plate 344 is bridged in the vehicle width direction of the
vehicle body frame 324, and the input shaft 327, the main shaft
(rotational shaft) 341 and the intermediate shaft 342 are pivotally
supported on the plate 344 so as to be rotatable and substantially
in parallel to one another. A driving shaft 343 (FIG. 16) of the
auxiliary driving wheel 338 is provided below the intermediate
shaft 342, and the driving shaft 343 is rotatably journaled on the
vehicle body frame 324.
The input shaft 327 is journaled on the plate 344 by a pair of
bearing portions 333. The shaft end portion of one shaft end
portion of the input shaft 327 (at the right side of the vehicle
body in the third embodiment) is provided with a coupling unit 325
which is connected to a wind-up motor 336 installed in a station
when the conveying vehicle 310 is stopped at the station concerned.
This coupling unit 325 is located inside the vehicle body frame 324
so that it does not project outwardly from the vehicle body 324,
and it is engaged with a motor-side coupling unit 321 fixed to the
motor shaft 336a of the wind-up motor 336 through an opening (not
shown) formed in the body 323.
As described above, according to the third embodiment, each work
station 302a is provided with the wind-up motor 336 which is
connected to the energy stocking mechanism 334 of the conveying
vehicle 310 and stocking power in the spiral spring 332 of the
energy stocking mechanism 334. Therefore, it is unnecessary to
provide the conveying vehicle 301 with the wind-up motor 336 for
winding the spiral spring 332, and thus weight saving and
compactness of the conveying vehicle 310 can be implemented.
Furthermore, only rotational driving force may be supplied from the
wind-up motor 336 of each of the work stations 302a to 302c through
the input shaft 327 to the energy stocking mechanism 334 of the
conveying vehicle 310, and the elastic force can be more easily
stocked in the spiral spring 332 even in a water-wetted workshop as
compared with the case where the auxiliary motor is installed in
the conveying vehicle and electric power is directly supplied from
the external source to the auxiliary motor provided to the
conveying vehicle.
In the third embodiment, for example, the wind-up motor 336
installed in the work station 302a is mounted on a carriage 390
whose height is set to be substantially identical to the height of
the motor shaft 335a and the input shaft 327, and by moving the
carriage 390 in the vehicle-width direction of the conveying
vehicle 310, the motor-side coupling unit 321 of the wind-up motor
336 is engaged with or separated from the coupling unit 325 of the
input shaft 327. Furthermore, the input shaft 327 is provided with
a brake 335 and a first sprocket 337. The brake 335 comprises an
electromagnetic brake, for example, and it permits or prohibit
rotation of the input shaft 327 under the control of the controller
322.
The main shaft 341 is divided into a first shaft (first rotational
shaft) 341a and a second shaft (second rotational shaft) 141b, and
these first and second shafts 341a and 341b are journaled on the
plate 344 by respective bearing portions 346 and 347. A cylindrical
casing 345 having a bottom is fixed to the axial end portion of the
second shaft 341b, and the shaft end portion of the first shaft 341
extends and the scroll type spiral spring 332 is mounted in the
casing 345. One end of the spiral spring 332 is fixed to the inner
wall surface 345 of the casing 345, and the other end of the spiral
spring 332 is fixed to the outer periphery of the shaft end portion
of the first shaft 341a. Accordingly, the spiral spring 332 is
wound up around the first shaft 341a on the basis of the rotation
of the first shaft 341a and the second shaft 341b. In the third
embodiment, the inner wall surface 345a of the casing 345 functions
as a parallel portion extending in parallel to the shaft end
portion of the first shaft 341a.
A second sprocket 348 which is connected through the first sprocket
337 and the chain 339 is provided to the shaft end portion at the
opposite side to the casing 345 of the second shaft 341b, and a
first one-way clutch 349 is provided between the second sprocket
348 and the second shaft 341b.
The first one-way clutch 349 is designed as a mechanical clutch.
When the second sprocket 348 is rotated in the normal direction
(the direction of the rotation based on the wind-up motor 336), the
first one-way clutch 349 is engaged with the second shaft 341b.
When the second sprocket 348 is rotated in the reverse rotational
direction, the above engagement is released, and the first one-way
clutch 349 slips.
A third sprocket 350 disposed between the second sprocket 348 and
the casing 345 and an input clutch 351 for performing a switching
operation so that the third sprocket 350 and the second shaft 341b
can be freely brought into contact with or separated from each
other. For example, the input clutch 351 is designed as an
electromagnetic type clutch, and when the input clutch 351 is
engaged under the control of the controller 322, the third sprocket
350 and the second shaft 341b are engaged with each other, and thus
the third sprocket 350 is rotated together with the second shaft
341b. On the other hand, when the engagement of the input clutch
351 is released, the engagement between the third sprocket 350 and
the second shaft 341b is released, and the third sprocket 350 slips
on the second shaft 341b.
Furthermore, a fourth sprocket 352, an output clutch 353 for
performing a switching operation so that the fourth sprocket 352
and the first shaft 341a can be freely brought into contact with or
separated from each other, and a spiral spring brake (output
limiter) 354 for adjusting the rotational amount of the first shaft
341a are disposed between the pair of the bearing portions 346 on
the first shaft 341a. The output clutch 353 is of the same type as
the input clutch 351, and in the second embodiment, the clutch
mechanism 340 is configured to have the input clutch 351 and the
output clutch 353.
The spiral spring brake 354 is an electromagnetic brake, for
example, and it permits or prohibits rotation of the first shaft
341a under the control of the controller 322. Furthermore, the
spiral spring brake 354 can adjust the rotational amount of the
first shaft 341a, and continuously or stepwise outputs elastic
force stocked in the spiral spring 332 of the energy stocking
mechanism 334 as power in the range from 0% to 100%. Accordingly,
the elastic force stocked in the spiral spring 332 is prevented
from being output at a burst and also the output amount thereof can
be controlled, so that the acceleration or speed of the conveying
vehicle 310 can be properly controlled. Furthermore, the driving
time of the wind-up motor 336 is reduced by suppressing the output
amount, and the power consumption to drive the auxiliary motor can
be reduced, so that energy saving can be implemented.
The intermediate shaft 342 is journaled by a pair of bearing
portions 355 at both the ends thereof on the plate 344, and the
intermediate shaft 342 is provided with a fifth sprocket 357
connected to the third sprocket 130 through a chain 356 and a sixth
sprocket 359 connected to the fourth sprocket 352 through a chain
358, and a second one-way clutch 361 is disposed between the sixth
sprocket 359 and the intermediate shaft 342.
As in the case of the one-way clutch 349, the second one-way clutch
361 is a mechanical type clutch which is engaged with the
intermediate shaft 342 when the sixth sprocket 359 rotates in the
normal rotational direction, and disengages from the intermediate
shaft 132 and slips when the sixth sprocket 359 rotates in the
reverse rotational direction.
A seventh sprocket 363 is provided between the sixth sprocket 359
and the bearing portion 355, and the seventh sprocket 363 is
connected to an eighth sprocket 367 (FIG. 19) provided to the
driving shaft 343 through a chain 365. Accordingly, the rotational
power of the main shaft 341 is transmitted through the intermediate
shaft 342 to the driving shaft 343, and the auxiliary driving wheel
338 is driven.
Furthermore, wheel brakes 369 for regulating the rotation of the
intermediate shaft 342 are disposed between the fifth sprocket 357
and the sixth sprocket 359 on the intermediate shaft 342. These
wheels brakes 369 are electromagnetic brakes, for example, and
under the control of the controller 322, they reduce the rotational
speed of the intermediate shaft 342 or stop the rotation of the
intermediate shaft 342 to thereby control the speed of the
conveying vehicle 310.
As shown in FIGS. 16 and 18, the loading portion 120 has a mount
table 316 as a table on which a work W is mounted, and an elevating
device 360 which can move the mount table 316 in an up-and-down
direction and hold the mount table 316 and the work W at a desired
height position.
The elevating device 360 comprises a hydraulic cylinder (elevating
mechanism) 364 for elevating the mount table 316 through a rod 362
fixed to the substantially center lower surface of the mount table
316, and a hydraulic circuit 366 (see FIG. 18) for driving the
hydraulic cylinder 364. The elevating operation of the mount table
316 is executed while the mount table 316 is guided by rails 370
extending in the up-and-down direction of the vehicle in parallel
to the rod 362 at both the sides in the vehicle width direction of
a vertical plate 368 provided at the rear portion of the mount
table 316, and guide recess portions 372 which are fixed to the
vehicle body frame 324 side and slidably fitted to the rails
370.
As shown in FIG. 18, the hydraulic circuit 366 is connected through
a control valve mechanism 376 to each of an upper chamber 364a and
a lower chamber 364b of a hydraulic cylinder 364 which are
compartmented by a piston 374 linked to the rod 362. The control
valve mechanism 376 is a valve device for properly switching the
intercommunication state with each of the upper chamber 364a and
the lower chamber 364b of the hydraulic circuit 366 and also
properly switching the flow direction of operating oil, and the
operation of the control valve mechanism 376 is controlled by the
controller 322.
A pump 378 for pressurizing and fluidizing the operating oil in the
circuit and a generator (electric generator) 380 which receives the
pressure or flow of the operating oil to generate electric power
are disposed in the hydraulic circuit 366. The power generated by
the generator 380 is charged in an auxiliary battery 382 comprising
an electricity storage element such as a capacitor or the like, a
secondary battery or the like, and then used as driving power for
the pump 378. When the power of the auxiliary battery 382 is
insufficient for the driving power of the pump 378, the battery 312
may be used. Furthermore, it is needless to say that the auxiliary
battery 382 is not provided and the power generated in the
generator 380 is charged in the battery 312. In this case, the
weight of the conveying vehicle 310 is reduced by only the weight
of the removed auxiliary battery 382.
The conveying vehicle 310 as described above runs by properly
driving the main driving wheel 330 and the auxiliary driving wheels
338 under the control of the controller 322. However, wheels 384a
to 384d which are driven and rotated during the running of the
vehicle based on the main driving wheel 330 and the auxiliary
driving wheel 338 are further supported through shafts by the
vehicle body frame 324 (see FIG. 16). The wheels 384a and 384b
serving as the front wheels in the forward running direction (the
direction of the arrow in FIG. 5) of the conveying vehicle 310 may
be made to function as steering wheels steered under the control of
the controller 322, for example, or the wheels 384c and 384d
serving as the rear wheels may be made to function as steering
wheels.
Furthermore, a sensor 388 (see FIG. 17) for detecting the magnetic
field of a magnetic tape 386 (see FIG. 20) which is attached onto a
passage on which the conveying vehicle 310 runs in a factory and
guides the conveying vehicle 310 is provided at the vehicle bottom
surface side of the conveying vehicle 110. Accordingly, the
conveying vehicle 10 can be magnetically induced. In place of the
above method of guiding the conveying vehicle 310, a method of
laying down a rail on the floor surface and inducing the conveying
vehicle along the rail or other methods may be used.
Next, the running operation of the conveying vehicle 310 according
to the third embodiment will be described.
The conveying vehicle 310 is basically controlled under the control
of the controller 322 so that it runs (starts running) by using the
auxiliary power unit 318 when it starts running from the stopped
state and also runs by using the main power unit 314 when it runs
normally after the start of running.
For example, when the conveying vehicle 310 is stopped at each of
the standby station and the work stations 302a to 302c (FIG. 14) is
stopped, the battery 312 of the conveying vehicle 310 is charged by
the external power source 331 provided to each of the work station
320a to 302c. Here, when the conveying vehicle 310 runs (starts
running) by using the auxiliary power unit 318, the wind-up motor
336 connected to the external power source 331 is driven, and the
spiral spring 332 of the energy stocking mechanism 334 is wound up
by the driving force of the wind-up motor 336.
At this time, the controller 322 sets the brake 335 to a release
state (OFF), sets the spiral spring brake 354 to an operating state
(ON) and sets the input clutch 351 and the output clutch 353 to a
separation state (OFF). That is, by operating the spiral spring
brake 354, the first shaft 341a is fixed so that it does not
rotate, and also by separating the input clutch 351, when the
second shaft 341b is rotated, this rotation is prevented from being
transmitted to the intermediate shaft 342.
When the motor-side coupling unit 321 of the wind-u motor 336 is
engaged with the coupling unit 325 of the input shaft 327 and the
wind-up motor 336 is driven, as shown in FIG. 19A, the rotation in
the normal rotational direction of the wind-up motor 336 is
transmitted to the second shaft 341b through the input shaft 327,
the first sprocket 337, the chain 339, the second sprocket 348 and
the first one-way clutch 349, and thus the second shaft 341b is
rotated together with the casing 345, so that the spiral spring 332
is wound up around the first shaft 341a. Under this state, elastic
force for rotating the second shaft 341b in the reverse rotational
direction occurs in the spiral spring 332. Therefore, when the
spiral spring 332 is wound up, the controller 322 operates (turns
on) the brake 335 provided to the input shaft 327. Accordingly, the
input shaft 327 and the second shaft 341b are fixed so that they
does not rotate in the reverse rotational direction. Therefore, the
wind-up motor 336 can be detached from the input shaft 327 by
separating the above coupling unit. As described above, in the
energy stock mechanism 334, the power (rotational torque) of the
wind-up motor 336 is converted to the elastic force of the spiral
spring 332 and stocked.
Next, after the charging of the battery 312 by the external power
source 331 and the stock of the elastic force in the energy
stocking mechanism 334 are completed, a preparation for start of
running (start moving) is made. That is, the controller 122 sets
the output clutch 353 to a connection state (ON). Accordingly, the
fourth sprocket 352 and the first shaft 341a are engaged with each
other, and the fourth sprocket 352 can be rotated together with the
rotation of the first shaft 341a, so that the power (rotational
force) of the first shaft 341a is allowed to be transmitted to the
auxiliary driving wheel 338 through the intermediate shaft 342 and
the driving shaft 343. In this case, the holding based on the
spiral spring brake 354 which sets the first shaft 341a to the
rotation-stopped state, and the holding based on the motor brake
336a which sets the second shaft 341b to the rotation-stopped state
are continued.
When the spiral spring brake 354 is released, as shown in FIG. 19B,
the elastic force of the spiral spring 332 is released, so that the
first shaft 341a is roundly rotated. Accordingly, the rotational
driving force of the first shaft 141a is transmitted to the driving
shaft 343 through the fourth sprocket 352, the chain 358, the sixth
sprocket 359, the second one-way clutch 361, the intermediate shaft
342, the seventh sprocket 363, the chain 365 and the eighth
sprocket 367, whereby the driving shaft 343 is rotated.
Accordingly, the auxiliary driving wheel 338 is rotated so that the
conveying vehicle 310 moves forwardly, and thus the conveying
vehicle 310 can start running (moving).
With respect to the start of running based on the auxiliary power
unit 318 as described above, the first shaft 341a is rotated to
apply a rotational torque to the auxiliary driving wheel 338 at
least until the elastic force stocked in the spiral spring 332 is
released. Furthermore, the second one-way clutch 361 is provided
between the intermediate shaft 342 and the sixth sprocket 359.
Therefore, even when the elastic force stocked in the spiral spring
332 is released and the rotational speed of the first shaft 341a is
lower than the rotational speed of the intermediate shaft 342, the
second one-way clutch 161 slips and thus the rotation of the
intermediate shaft 342 and the driving shaft 343 is continued, so
that the conveying vehicle 310 can run by some degree of distance
with the inertial force thereof. Accordingly, the conveying vehicle
310 can run with only the elastic force stocked in the spiral
spring 332 of the energy stocking mechanism 334 among working
stations in a factory by designing the conveying vehicle 310 in
consideration of the vehicle weight of the conveying vehicle 310
containing a work to be conveyed, the characteristic of the spiral
spring 332, losses of the respective bearings, etc., for
example.
A clutch (not shown) may be disposed between the driving shaft 328a
of the running motor 328 and the main driving wheel 330 so that the
clutch concerned is set to a separation state when the conveying
vehicle 310 starts running by the auxiliary power unit 318. In this
case, the load on the running motor 328 which is not used at the
running start time can be reduced, and also the load from the
running motor 328 can be effectively suppressed from affecting the
running starting operation.
When the running of the conveying vehicle 310 is continued after
the start of running based on the auxiliary power unit 318, the
controller 322 drives the main power unit 314, and drives the
running motor 328 with the power from the battery 312, whereby the
conveying vehicle can continuously run as a normal
electrically-operated vehicle.
Subsequently, when the conveying vehicle 310 runs, the controller
322 executes an operation of regenerating the rotational power of
the auxiliary driving wheel 338 to the spiral spring 332 of the
energy stocking mechanism 334. In this case, from the viewpoint of
energy, it is more desired to execute the regenerating operation
during deceleration of the conveying vehicle 310 than during
running of the conveying vehicle 310 based on the running motor
328.
When the conveying vehicle 310 shifts to a decelerating operation,
the controller 322 sets the spiral spring brake 354 to the
operating state (ON), and also sets the input clutch 351 to the
connection state (ON), whereby the third sprocket 350 and the
second shaft 341b are engaged with each other. Accordingly, the
rotational driving force of the auxiliary wheel 338 is transmitted
to the second shaft 341b through the driving shaft 343, the eighth
sprocket 367, the chain, the seventh sprocket 363, the intermediate
shaft 342, the fifth sprocket 357, the chain 356 and the third
sprocket 350, and the casing 345 is rotated together with the
second shaft 341b, whereby the spiral spring 332 is wound up around
the first shaft 341a.
As described above, in this construction, the input clutch 351 is
set to the connection state (ON) during the running of the
conveying vehicle 310, whereby the rotational driving force of the
auxiliary driving wheel 338 can be regenerated (stocked) as the
elastic force of the spiral spring 332. Therefore, in the next
running operation, the wind-up motor 336 may be driven at a station
to supplement the spiral spring 332 of the energy stocking
mechanism 334 with elastic force which is not enough even by the
regeneration. Accordingly, the power for stocking the elastic force
into the spiral spring 332 can be reduced, and the power
consumption for driving the wind-up motor 336 can be reduced, so
that energy saving can be implemented.
In a general vehicle in which elastic force is stocked by winding
up a spiral spring around a rotational shaft, the rotational
direction of the rotational shaft when elastic force is stocked is
opposite to the rotational direction of the rotational shaft when
the stocked elastic force is output (released). Therefore, when
elastic force is output to a shaft rotating in a fixed direction
under normal running (for example, forward running) and elastic
force is generated by using the rotational driving force of this
shaft as in the case of the driving shaft of the conveying vehicle,
it is necessary to provide a mechanism for reversing the rotational
shaft of the spiral spring between the output operation and the
regenerating operation. Therefore, the construction of the vehicle
is complicated.
On the other hand, according to the construction of this
embodiment, the energy stocking mechanism 334 has the divided first
and second shafts 341a and 341b and the spiral spring 332 disposed
between these shafts, and thus the first shaft 341a and the second
shaft 341b can be rotated in the same rotational direction in the
output operation of outputting the elastic force stocked in the
spiral spring 332 to the auxiliary driving wheel 338 and in the
regenerating operation of regenerating (stocking) the rotational
driving force of the auxiliary driving wheel 338 as the elastic
force into the spiral spring 332. Therefore, it is unnecessary to
provide a mechanism for reversing the rotation of the rotational
shaft between the elastic force stocking (regenerating) operation
and the elastic force outputting operation, and thus the
construction of the energy stocking mechanism can be
simplified.
As described above, according to the conveying vehicle 310 of the
second embodiment, the auxiliary driving wheel 338 is driven by the
elastic force stocked in the spiral spring 332 of the energy
stocking mechanism 334, whereby the conveying vehicle can start
running from the stopped state. In this case, the wind-up motor 336
for winding up the spiral spring 332 is driven by the external
power source 331 when the conveying vehicle 310 is stopped.
Therefore, it is unnecessary to consume the battery 312, and also
the wind-up motor 336 can be driven simultaneously with charging of
the battery 312, so that no time loss occurs. Furthermore, after
the conveying vehicle 310 starts running by using the auxiliary
power unit 318, the conveying vehicle can electrically run by using
the main power unit 314 as in the case of a general
electrically-operated vehicle. Therefore, the conveying vehicle can
run on a desired passage by a desired distance.
Furthermore, in general, the power amount (current amount) of the
motor under low-speed rotation is larger than that under
predetermined high-speed rotation, and also the driving torque
required to start running from a stopped state is very larger than
the driving torque under a stationary running state. In other
words, if the conveying vehicle 310 is made to start running by
using the running motor 328, the running motor 328 must rotate at a
low speed and output a high torque. Therefore, the power
consumption thereof would be extremely larger that the power
consumption of the wind-up motor 336 for winding the spiral spring
332.
On the other hand, the start of running of the conveying vehicle
310 can be covered by the elastic force of the spiral spring 332,
and thus a low-power and compact motor can be used as the running
motor 328. Particularly, with respect to the conveying vehicle 310
which is also required to convey a work as a heavy load, the load
associated with the start of running is very large, and the effect
thereof is remarkable. Furthermore, in the conveying vehicle 310,
it is hardly required to use the battery 112 at the running start
time. Therefore, the battery 312 can be designed to be small in
capacity and compact in size, and thus weight saving and energy
saving for the conveying vehicle 110 can be performed. In addition,
since the spiral spring is used as the elastic member constituting
the energy stocking mechanism 334, the auxiliary power unit 118 can
be constructed simply and in low cost.
In the conveying vehicle 310 of the first embodiment, the conveying
vehicle 310 according to this invention can be made to run by
selectively driving the main power unit 314 and the auxiliary power
unit 318 as described above, whereby the energy saving can be more
greatly performed as compared with the normal electrically-operated
vehicle. With respect to the elevating device 360 constituting the
mount portion 320 on which a work is mounted, it is provided with
the generator 380, the auxiliary battery 382, etc., whereby energy
saving can be further greatly enhanced.
That is, in the elevating device 360, before the work W is mounted
on the mount table 316, under the control of the controller 322,
the control valve mechanism 376 is first switched and the pump 378
is driven, and oil pressure is applied in the hydraulic circuit 366
in a direction of a broken-line arrow P in FIG. 18. Accordingly,
the lower chamber 364b is pressurized, and the mount table 116 is
upwardly moved to a desired height position through the piston
374.
Subsequently, the work W is mounted on the mount table 316. At this
time, by preventing leakage of hydraulic pressure from the lower
chamber 364b through the control valve mechanism 376 and keeping
the pressurized state, the height position of the work W can be
kept easily and with saved power without keeping the driving of the
pump 378.
When the work W is mounted on the mount table 316 or the work W
held at the desired height position is downwardly moved, the
control valve mechanism 376 is properly controlled so that the
mount table 316 is downwardly moved by the weight of the work W and
the mount table 316 without driving the pump 378. That is, the
control valve mechanism 376 is controlled to be switched so that
the operating oil can flow out from the lower chamber 364b and the
flow-out operating oil flows through the hydraulic circuit 366 in
the direction of a solid-line arrow Q. Accordingly, the operating
oil flows out from the lower chamber 364b which is compressed due
to the downward movement of the piston 374 in connection with the
downward movement of the work W and the mount table 316, so that a
vane wheel (not shown) or the like of the generator 380 is rotated
to generate power and the generated power is stocked in the
auxiliary battery 382.
In the elevating device 360, the pump 378 is driven with the
stocked power from the auxiliary battery 382, and the mount table
316 can be returned to the desired height position. When the power
from the auxiliary battery 382 is insufficient to return the mount
table 316 to the desired height position, the battery 312 may be
used in combination.
As described above, in the elevating device 360, power can be
generated in the generator 380 by using the weight of the work W
and the weight of the mount table 316, and utilized as a driving
source of the pump 378 which is used to move the mount table 316
upwardly again through the auxiliary battery 382. That is, the
elevating device 360 has an energy regenerating mechanism for
regenerating the potential energy of the work W mounted on the
mount table 316 at the desired height position as electrical energy
by using the hydraulic circuit 366 and the generator 380, and
charging the auxiliary battery 382. Therefore, basically, the
energy required to move the mount table 316 upwardly and downwardly
can be covered by the elevating device 360 itself.
Accordingly, the conveying vehicle 310 has the elevating device 360
having the energy regenerating mechanism described above, and thus
it is unnecessary to use power of the battery 312 or the like as
elevating energy of the mount table 316. Therefore, the battery 312
can be designed to be smaller in capacity and more compact in size,
and thus the energy saving of the conveying vehicle 310 can be more
greatly enhanced.
As shown in FIG. 18; in the conveying vehicle 310, the electrical
energy which is regenerated by the elevating device 360 and output
from the generator 380 may be used not only to charge the auxiliary
battery 382, but also to derive the wind-up motor 336 of the
auxiliary power unit 318. Accordingly, even when it is unnecessary
to charge the battery 312 under the stopped state or no external
power source 331 is provided to a station or the like at which the
conveying vehicle is stopped, the wind-up motor 336 may be driven
with the power from the auxiliary battery 382 without using any
power from the battery 312 to stock elastic force in the energy
stocking mechanism 334.
In addition, the mount table 316 on which the work W is mounted may
be downwardly moved at a desired timing to generate power when the
conveying vehicle 310 is stopped, whereby the power from the
generator 380 is supplied to the auxiliary motor 136 to stock
elastic force in the spiral spring 332 when the conveying vehicle
310 is stopped. That is, at the stop time of the conveying vehicle
310, the loading of the work W onto the mount table 316 and the
stock of elastic force into the spiral spring 332 can be
simultaneously performed, and after the work W is loaded, the quick
start of running by the auxiliary power unit 318 can be performed.
Therefore, further energy saving and speed-up of the conveying work
can be performed.
Next, the conveying system 300 to which the conveying vehicle 310
according to the third embodiment is applied will be described.
First, as shown in FIG. 20, a conveying vehicle 310 which is on
standby at a standby station 304 of the conveying system 300 is
supplied with power from the external power source 331 to charge
the battery 312 and stock elastic force in the energy stocking
mechanism 334 by the driving force of the wind-up motor 336. After
these works are completed, the conveying vehicle 310 concerned
starts running by using the auxiliary power unit 318 as a driving
source. The conveying vehicle 110 which starts running is guided by
a magnetic tape 386 by detecting magnetic field through a sensor
388 under the control of the controller 322, and reaches a first
work station 302a.
In this case, in the energy stocking mechanism 334, the rotational
driving force of the auxiliary driving wheels 338 are regenerated
as elastic force in the spiral spring 332 under the deceleration of
the conveying vehicle 310. Therefore, at the work station 302a, the
wind-up motor 336 may be driven to supplement the spiral spring 332
of the energy stocking mechanism with elastic force which is not
enough even by the regeneration. Accordingly, the power for
stocking the elastic force in the spiral spring 332 can be reduced,
and the power consumption for driving the wind-up motor 336 can be
reduced, so that energy saving can be performed.
When the distance between the standby station 304 and the work
station 302a is within a sufficiently reachable distance at which
the conveying vehicle starting from the standby station 304 reaches
the work station 302a by only the power of the auxiliary power unit
318, it is unnecessary to drive the main power unit 314 after the
conveying vehicle 110 starts running, and thus the power can be
extremely saved. The same is applied to the movement between the
following respective work stations.
Subsequently, for example, a work W such as a vehicle engine or the
like is loaded onto the mount table 316 of the conveying vehicle
310 reaching the work station 302a by a working robot 306a provided
to the work station 302a. Furthermore, in the elevating device 360,
energy is regenerated by using the weight of the work W to charge
the auxiliary battery 382 as occasion demands.
When power generation is executed in the elevating device 360
substantially simultaneously with the loading of the work W, the
wind-up motor 336 may be driven with the generated power, and
elastic force can be stocked in the energy stocking mechanism 134.
In some cases, the external power source 331 may be omitted from
the work station 302a.
The conveying vehicle 310 on which the work W is loaded starts
running by using the auxiliary power unit 318 as the driving
source, and reaches the second work station 302b. At the second
work station 302b, for example, a desired part (not shown) is
assembled with the work W conveyed from the work station 302a by a
working robot 306b.
Subsequently, when the conveying vehicle 310 reaches the third work
station 302c, for example, a working robot 306c conveys the work W
assembled with the desired part from the mount table 316. At the
same time, the wind-up motor 336 is engaged with the input shaft
327, and elastic force is stocked in the energy stocking mechanism
334 by the external power source 331 again.
Thereafter, the conveying vehicle 310 starting from the work
station 302c runs on a passage along which it returns to the
standby station 304 again. At this time, by driving the main power
unit 314 after the running start based on the auxiliary power unit
318, the convey vehicle 310 can easily come back to the standby
station 304 even when the distance of the return passage to the
standby station 304 is relatively long. The conveying vehicle 310
returning to the standby station 304 is supplied with power from
the external power source 331 again, and charging of the battery
312 and the stock of elastic force in the energy stocking mechanism
334 are performed. Furthermore, by driving the elevating device 360
with the auxiliary battery 82 charged at the work station 302a, the
mount table 316 can be upwardly moved to a desired height
position.
As described above, in the conveying system 300, the conveying
vehicle 310 can move between the respective work stations or the
like with only the power of the auxiliary power unit 318, and thus
the work can be performed with extremely saved power. Of course,
the main power unit 314 can be driven during the movement between
the respective work stations or the like as occasion demands.
In addition, the conveying vehicle 310 can run by using the running
motor 328 as in the case of the normal electrically-operated
vehicle. Therefore, even when the running passage is relatively
long, the conveying vehicle can surely move on the running passage,
and the degree of freedom of the design of the moving passage can
be enhanced. Therefore, as indicated by a broken line of FIG. 20,
the running passage of the conveying vehicle 310 can be easily
changed by re-attaching the magnetic tape 386 and slightly changing
the control program of the controller 322.
As described above, according to the third embodiment, the vehicle
system contains the conveying vehicle having the energy stocking
mechanism 334 containing the spiral spring 332 which is connected
to the auxiliary driving wheel 338 of the vehicle body frame 324
and can convert power to elastic force, stock the elastic force and
output the stocked elastic force as power to the auxiliary driving
wheel 338, and the work stations 320a to 302c at which the
conveying vehicle 310 is stopped. Each of these work stations 302a
to 302c is provided with the wind-up motor 336 which is connected
to the energy stocking mechanism 334 of the conveying vehicle 310
to stock power into the spiral spring 332 of the energy stocking
mechanism 334 when the conveying vehicle 310 is stopped at each of
the work stations 302a to 302c. Therefore, it is unnecessary to
provided the conveying vehicle 310 with the wind-up motor 336 for
winding up the spiral spring 332, and thus the weight and size of
the conveying vehicle 310 can be reduced.
Furthermore, only the rotational driving force may be supplied from
the wind-up motor 336 of each of the work stations 302a to 302c
through the input shaft 327 to the energy stocking mechanism 334 of
the conveying vehicle 310, and elastic force can be easily stored
in the spiral spring 332 even in a water-wetted working field. In
addition, the wind-up motor 336 is not provided to each conveying
vehicle 310, but to each of the work stations 302a to 302c, and
thus when the number of the work stations is smaller than the
number of the conveying vehicles, the number of the
electrically-operated motors to be installed is reduced, and thus
the system construction can be implemented in low cost.
Furthermore, according to the third embodiment, the conveying
vehicle 310 has the clutch mechanism 340 for performing the
switching operation between the output of power from the spiral
spring 332 of the energy stocking mechanism 334 to the auxiliary
driving wheel 338 of the vehicle body frame 324 and the
regeneration of power from the auxiliary driving wheel 338 to the
spiral spring, and when the conveying vehicle 310 moves between the
work stations 302a to 302c, the conveying vehicle 310 runs with the
power stocked in the energy stocking mechanism 334, and the clutch
mechanism 340 is switched to the regeneration side during running
so as to enable regeneration of power from the auxiliary driving
wheel 338 to the spiral spring while the conveying vehicle 310
runs. Accordingly, by switching the clutch mechanism 340, the power
of the auxiliary driving wheel 338 during running can be
regenerated (stocked) as the elastic force of the spiral spring 332
of the energy stocking mechanism 334.
Therefore, at a work station, the wind-up motor 336 may be driven
to supplement the spiral spring 332 of the energy stocking
mechanism 334 with extra elastic force to be added to insufficient
elastic force stocked by only the regeneration. Accordingly, the
power for stocking the elastic force into the spiral spring 332 can
be reduced, and the power consumption for driving the wind-up motor
336 can be reduced, so that energy saving can be performed.
Furthermore, according to the third embodiment, the conveying
vehicle has the main driving wheel 330 for driving the vehicle body
frame 324, and the running motor 328 for driving the main driving
wheel 330, and the power stocked in the spiral spring of the energy
stocking mechanism 334 assists the driving force of the running
motor 328 when the conveying vehicle starts running. Therefore, a
low-power and compact motor can be used as the running motor 328,
and weight saving and energy saving for the conveying vehicle 310
can be performed. Furthermore, the clutch mechanism 340 is switched
to the regeneration side when the conveying vehicle is located at a
position near to the end point of the distance between the
respective work stations, and thus the power can be regenerated
from the auxiliary driving wheel to the spiral spring 332 during
running. Therefore, at a work station where the conveying vehicle
stops, the wind-up motor 336 may be driven to supplement the spiral
spring 332 of the energy stocking mechanism 334 with elastic force
to be added to insufficient elastic force stocked by only the
regeneration. Accordingly, the power for stocking the elastic force
into the spiral spring 332 can be reduced, and the power
consumption for driving the wind-up motor 336 can be reduced, so
that energy saving can be performed.
The present invention is not limited to the above embodiments, and
various modifications may be made without departing from the
subject matter of the present invention.
For example, in the above embodiments, the conveying vehicle 10,
110, 310 includes the main power unit 14, 114, 314 having the
running motor 28, 128, 328, and the energy stocking mechanism 34,
134, 334 is used as an assist when starting running. However, for
example when a running distance is predetermined as in the case of
running between work stations, by designing the energy stocking
mechanism 34, 134, 334 so as to meet a condition, the main power
unit 14, 114, 314 may be omitted.
Furthermore, the conveying vehicle 10, 110, 310 of the above
embodiments has the running motor 28, 128, 328 as the running
driving source for the main power unit 14, 114, 314. It is needless
to say that other driving sources such as an internal combustion
engine such as an engine or the like, a, spiral spring, etc. may be
used. In the above embodiments, the battery 12, 112, 312 is
provided as the power supply unit for supplying power to the
running motor 28, 128, 328. However, a power line may be laid down
on the floor or the like so that power is supplied to the running
motor through the power line. Furthermore, the battery 12, 112, 312
is not charged by only the external source, but a solar panel may
be provided to a conveying vehicle so that the solar panel and the
external power source are used in combination.
Furthermore, in the above embodiment, the electrically-operated
auxiliary motor 36, 136 or the wind-up motor 336 is used as the
driving source for power stocking, however, the present invention
is not limited to these elements. For example, an air motor which
is used for an impact wrench or the like and rotationally driven by
using compressed air as a driving source may be used insofar as it
applies rotational driving force to the main shaft 42 and the
second shaft 141b, 341b.
The conveying vehicle 10, 110, 310 may be designed so that it can
normally run as in the case of a general electrically-operated
vehicle while starting running, running at a constant-speed,
accelerate speed, etc. by the driving force obtained by the main
power unit 14, 114, 314 having the running motor 28, 128, 328
driven with power from the battery 12, 112, 312 and the main
driving wheel 30, 130, 339. That is, the conveying vehicle 10, 110,
310 can run substantially in the same manner as a general
electrically-operated vehicle, and thus it can retrogress (back
away), etc., and thus the degree of freedom of the construction of
the conveying system 100, etc. can be further enhanced.
Furthermore, the auxiliary power unit 18, 118, 318, etc. containing
the energy stocking mechanism 34, 134, 334, etc. may be constructed
as a traction vehicle which is configured separately from the main
power unit 14, 114, 314. In this case, the traction vehicle may be
externally attached to the conveying vehicle having the main power
unit 14, 114, 314 and the loading portion 20, 120, 320 so as to
pull or push the conveying vehicle, whereby the function based on
the auxiliary power unit 18, 118, 318 can be easily added to
existing AGV or the like.
Furthermore, the conveying vehicle 10, 110, 310 may be modified so
that the loading portion 20, 120, 320 is omitted, and it may be
configured as an electrically-operated vehicle which transports
another burden in place of conveyance of a work W and also in which
persons get.
According to the second embodiment and the third embodiment, in the
energy stocking mechanism 134, 334, the casing 145, 345 is
connected to the second shaft 141b and 341b. However, the casing
may be connected to the first shaft 141a, 341a. Furthermore, in the
second embodiment and third embodiment, the cylindrical casing 145,
345 is fixed to the second shaft 141b, 341b. However, when it is
configured to extend in parallel to the shaft end portion of the
first shaft 141a, 341a, a substantially L-shaped member may be
fixed to the shaft end portion of the second shaft 141b, 341b.
* * * * *